Std. 10 Physics Capsule by Alif Muhammed

8/9/2019 Std. 10 Physics Capsule by Alif Muhammed

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CAPSULE PHYSICS

(A SMALL COMPANION MATERIAL FOR PHYSICS)

PHYSICS

CL SS X

ALIF MUHAMMED.A


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PREFACE

I feel immense pleasure in presenting the book CAPSULE PHYSICS(A SMALL COMPANION MATERIAL FOR PHYSICS) for class x.

Salient features:

Covers all the facts and aspects of syllabus in the form of a capsule.

Number of worked out examples are given in all chapters at

appropriate places for the quick revision and assessment of

understanding of the topic.Model question paper is also included at the end of the book.

Use of very simple and lucid language.

First thanks go to my father and mother and GODand my friends &

Smart Caf, Edamon. My Sincere thanks go to Mrs. Jayakumary.S

[Former Principal KUCTE, ANCHAL].

Please read this text book carefully, and then send your suggestions forimproving the quality and usefulness of the book.

Alif Muhammed. A

Banglavu Murupel Puthen Veedu

Edamon Post

Punalur

Pin 691307

Mob: 9995858447

E mail: [email protected]


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ndex

CHAPTER PAGE NO

1. EFFECTS OF ELECTRIC CURRENT ..4

2. ELECTROMAGNETIC INDUCTION .12

3. GENERATION AND DISTRIBUTION OF

ELECTRIC POWER .19

4. SOUND..26

5. OPTICAL PHENOMENA..35

6. ELECTRONICS.. 40

7. OUR UNIVERSE....49

8. S.S.LC MODEL QUESTION .... 51


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1. EFFECTS OF ELECTRIC CURRENT

MAIN CONTENTS HEATING EFFECT OF ELECTRIC CURRENT LIGHTING EFFECT OF ELECRIC CURRENT CHEMICAL EFFECT OF ELECTRIC CURRENT

HEATING EFFECT OF ELECTRIC CURRENT

Joules Law

The law states that Heatdeveloped in a conductor by the passage of electric current is equal to theproduct of the square of the current and the resistance of the conductor and the time of the flow of

current.

I.e.: H =I2Rt

H- Heat (joule)

Icurrent (A)

t- Time (s)

Equations of Joules law from Ohms law

By Ohms law R =V/I, I = V/R

1. H = I2Rt = = V

2t /R

2. H = I2R t = =VIt

Q1. What are the factors affecting heat produced by a current passing conductor?

Q2.State and explain joules law?

Additional l information

We know that H =I2

Rt,

Then 1. t=H/I2R

2. R = H/I2t

3. I2= H/Rt or I=

Q3. Find out the quantity of heat produced in a resistance of 10 , when 2A current is supplied to it for 60 s?

Ans: R = 10, I=2A, t =60 s, H=?

H = I2Rt

H = I2Rt

H = V2t /R

H =VIt


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H =22x 10 x 60 = 4 x10 X60 = 2400 J

MORE PROBLEMS

1 Calculate the time required to produce 24000 J of heat when a current of 2A flows through an electric kettle

under a supply of 240 v?

Ans : t =50 s

2 .Find the heat developed in a resistor of resistance 2000 when 2A current is supplied to for 5 minutes?

Ans: 2400000J

Characters of nichrome

1. High Resistance

2. High melting point

3. Ability to remain in red hot state for a longtime

4. Does not have high thermal expansion

5. Does not get oxidized at higher

temperature.

ELECTRIC POWER

Power is the work done per unit time, Power =work/time

Electric power is the work done by the electric current per unit time.

Electric power= =W/t=H/t

P = I2Rt/t equations of electric power is

P =I2R

Unit of power is J/s or watt (w)

Q4. Find out the power of an electric device of 200resistance which draws a current of 3A?

R =200

I = 3 A

P =?

P =I2R P= 3

2x 200=1800 w

Q5.An Electric device of resistance 20works in a 230 Vmains, find the power of the device?

R =20, V= 230V, P=?

P = V2/R =2302/20=2645w

Safety fuse wire

* It is an alloy of tin and lead

* low melting point

P= I2R

P = V2/R

P =VI


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Q6.Calculate the heat produced when a 500 W heater works for 10 minutes?

Ans : P=500W ,t=10X60=600S,

H=VIt=Pxt=500x600=300000J

RESISTANCE

Resistanceof an electrical conductor is the opposition to the passage of an electric current throughthat

conductor. It is denoted by R, and its unit is ohm (),

Factors affecting the resistance of a conductor

1. Length of the conductor ( )

2. Area of cross section of

the conductor(R )

4. Temperature of the

conductor

5. The nature of the material

Q7.Some material and there

resistivity are given below

Silver-1.53, copper-1.68, iron-10, mercury-94

a. Which among iron and mercury is a better conductor?

B .Which material is the best conductor? Why?

Q8. Acurrent of Y ampere is passed through a conductor of X ohm resistance for a period of Zsecond,

a. Find the heat developed in the conductor?

b. When the current through a conductor is doubled, the heat developed in it will be increased

by?

LIGHTING EFFECT OF ELECRIC CURRENT

Different Types of lamps

1. FILAMENT LAMP

2. FLURESCENT LAMP

3. DISCHARGE LAMP

1.( )

2.(R )

Then R , R= ,

(Rho) is a constant, and is called resistivity of

the conductor.

= ,Its unit is ohmmeter (m)

Resistivity is the resistance of a conductor having

unit length and unit area of cross section

Substance Resistivityx10

-8

m

Silver 1.59

Copper 1.68

Aluminum 2.82

Steel 2

Tungsten 5.5Nichrome 100

Carbon 3.5
https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CDEQFjAB&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FResistance&ei=6uEbU66OKsW3rgfD24DYDg&usg=AFQjCNHm2Su2u6BbbgGY74I8mLjOEM2NWAhttps://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CDEQFjAB&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FResistance&ei=6uEbU66OKsW3rgfD24DYDg&usg=AFQjCNHm2Su2u6BbbgGY74I8mLjOEM2NWAhttps://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0CDEQFjAB&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FResistance&ei=6uEbU66OKsW3rgfD24DYDg&usg=AFQjCNHm2Su2u6BbbgGY74I8mLjOEM2NWA


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4. LIGHT EMITTING DIODE

MAIN FUNCTION OF ELECTRIC LAMPS CONVERT ELECTRICAL ENERGY INTO

LIGHT ENERGY

FILAMENT LAMP (Incandescent lamp)

Main parts 1. Tungsten filament 2.Glass bulb, 3.Holder pin

Working: An incandescent light bulb, incandescent lampor incandescent light globeis anelectric

light which produces light with afilament wire heated to a high temperature by an electric current passing

through it, until it glows. The hot filament is protected from oxidation with a glass or quartz bulb that is filled

with inert gas or evacuated.

Filament lamp

DEMERIT OF THE FILAMENT LAMP:Main problem is major part of energy is lost in the form of heat.

.

DISCHARGE LAMP

Part-1.A Glass tube,

2. Glass tube filled with suitable gas,

3. Electrodes at both ends of the tubes

CHARACTRERISTICS OF TUNGSTEN

1. HIGH MELTING POINT

2. HIGH DUCTILITY

3. HIGH RESISTIVITY

5. HIGH RESISTANCE

5. ABILITY TO REMAIN IN WHITE HOT STATE

FOR A LONG TIME

INCANDESCENT MEANS GLOWING ON

BEING HEATED
http://en.wikipedia.org/wiki/Electric_lighthttp://en.wikipedia.org/wiki/Electric_lighthttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Filamenthttp://en.wikipedia.org/wiki/Incandescent_light_bulb#Filamenthttp://en.wikipedia.org/wiki/Electric_lighthttp://en.wikipedia.org/wiki/Electric_lighthttp://en.wikipedia.org/wiki/Electric_light


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Working

A High voltage is applied on the electrodes of the tube, then the gas gets ionized. As a result of the collision of

ions and electrons with unionized particle, the light is produced.

FLUORESCENT LAMP

Main parts:

1. Glass tube,

2. Heating coil

Working

When electricity is passed though the heating coil of the F-lamp it gets heated and electrons are emitted. The

tube in the lamp has mercury in it, due to the passage of electricity mercury gets evaporated, and then the

emitted electrons collide with mercury atoms. As a result, UV rays are produced from mercury atoms. These

UV rays are absorbed by the fluorescent materials and change into visible light.

CF lamps (Compact Fluorescent lamps)

A compact fluorescent lamp(CFL), also called compact fluorescent light, energy-saving light, and compact

fluorescent tube. It works with the help of an electronic circuit

Advantages of fluorescent lamps

Energy loss is less

Gives greater intensity of light

Majority of energy is converted into light energy

Shadow is minimized

Saves electrical energy

Disadvantages of fluorescent lamps

High initial cost

Useless fluorescent lamps became waste

Mercury and florescent material inside the discarded tubes as pollutants

The colour of the light produced in discharge lamp

depends on the nature of the gas that is used in the

discharge lamp Gas in the

discharge tube

Colour of light

Neon Orange

Nitrogen Red

Sodium Vapour Yellow

Mercury vapour white

Chlorine Green

Hydrogen Blue


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(CFL- LAMPS) (CFL- LAMP CIRCUIT)

LED (Light emitting diode)

LED is an electronic device which converts electrical energy into light energy, (An LED consists of two

elements of processed material called P-type semiconductors and N-type semiconductors. These two elements

are placed in direct contact, forming a region called the P-N junction.)

Benefits of LEDs compared with incandescent and fluorescent lamps

Low power requirement: Most types can be operated with battery power supplies

High efficiency

Long life

Lower initial cost

Produces cool light

LED light up very quickly

Uses of LED

Indicator lights

LCD panel backlighting:Specialized white LEDs are used in flat-panel computer displays.

Q9.The colour of light in the Neon lamp is orange

a. We can fill mercury vapour instead of Neon gas, predict the colour of light?

b. Explain how light is obtained from it?

Ans: a .white b.(refer) what?

Q10.In a circuit there is a resistance wire of length 20 cm , a boy cuts the resistance wire in to two equal halves

and one half is connected to the circuit, what will be the change in the intensity of bulb in the circuit?

Ans : The new length is 10 cm, we know that , and when the length of the resistance wire is reduced to half

of the original value, intensity of current increases and the bulb glows with more intensity.

L.E.D


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CHEMICAL EFFECT OF ELECTRIC CURRENT

Electro platingis the process of coating a metal on the surface of conductor by electrolysis. It is done by thehelp of a solution called electrolyte. This electrolyte contains the ions of the metal used and the ions move

towards the negative electrode.

Object to be electro

plated

Positive electrode Negative electrode Electrolyte

An iron spoon with silver Silver plate Iron spoon Silver nitrate solution

/mixed solution of

sodium cyanide and silvercyanide

An aluminum cup with

gold

Gold plate Aluminum cup A mixed solution of

sodium cyanide and gold

cyanide

The handle of a bicycle

with chromium

Chromium plate Handle of bicycle Chromic acid

Copper- Copper sulphate, Nickel- Nickel ammonium sulphate

Uses of electroplating

Improves the appearance

Prevents corrosion

To make artificial jewellery by electro plating gold or silver on jewellery made of cheaper metals

Situations in which chemical effect of electric current is used

Electroplating

Purification of metal

To extract metals from ore

Q11. Suppose an iron cup is to be electroplated with silver.

a. Which material is used as positive electrode?

b. Which solution is used as electrolyte?

c. Draw the arrangement of electroplating?

Q12.A wire of given material having length L and area of cross section A has a resistance of 4.what

would be the resistance of another wire of the same materials having length L/2 and area of cross section 2A?

Q13. Calculate the power of a heater of resistance 125 working on 230v mains?

Ans: P=423.3w


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Combination of resistors

Effective resistance in series R=R1+R2+R3+

Effective resistance in parallel = + +.

Q14.Two resistors 12, 6 are connected in series with 9v battery.

a. Draw the circuit diagram?

B . Calculate the effective resistance of the circuit?

c. Calculate the intensity of current through each resistor?

Ans : b. R=8 c .I=0.5A,

Q15.

A and B are two blubs

a. Which bulb has more resistance?

b. If the bulb A works on 125v, calculate the heat produced in 10 minutes?

Ans : a. Bulb B has more resistance because it has less power

b. H=7500J

Q16. Analyze the given figure and write about the effect of current utilized in each figure?

(A) (B) (C)

Q17. Calculate the heat produced in the circuit given below when current is passed for one minute through the

circuit? (R1=6 and R2=3,V=3V}

A

50W, 250V

B

25W, 250V


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.

Q18 .An electrical device of 250 work in 2 A current

a. find the power of this device?

B .How much energy will be consumed in one hour?

Q19. A silver cup is has to be electroplated with gold.

a. What are the materials needed for this?

b. What area the important points to be noted while doing this experiment?

c. What is the function of the battery?

Q20 .Write the following sentences in the correct order?

Gases are ionized, Rays are produced, and Collision between ions and molecule take place, High voltage is

given to the electrodes

Q21.It is dangerous to use a thick wire as fuse instead of a fuse wire, why?

Q22.How does safety fuse protect the appliance in an electric circuit?

2 .ELECTROMAGNETIC INDUCTION

MAIN POINTS

ELECTROMAGNETIC INDUCTION

ELECTRIC GENERATOR

MOVING COIL MICROPHONE MUTUAL INDUCTION

TRANSFORMER

SELF INDUCTION

FLEMINGS LEFT HAND RULE

MOVING COIL LOUDSPEAKER

DC MOTOR

ELECTROMAGNETIC INDUCTION

The process by which an emf is induced in a conductor when the magnetic flux linked with it changes. The emf

produced is called induced emf, and the resulting current is called induced current.


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Methods used to increase the induced emf

Increase the strength of the magnet

Increase the number of turns in the coil

Increase the speed of rotation of magnet or coil

AC and DC GENERATORS

AC and DC generator is a device working on the principle of ELECTROMAGNETIC INDUCTION

AC and DC generator is used to convert mechanical energy into electrical energy

AC generator

Main parts of AC generator are Output of AC generator

Field magnet Armature

Slip rings

Brush

If the coil completes one rotation in one second its frequency is said to be 1Hz


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DC Generator

Main parts

Field magnet

Armature

Split ring

Brush

Out put

The AC induced in the armature is converted into DC in the

External circuit by an arrangement called-split ring commutator.

Graphical representation of battery

emf

t

Moving coil microphone

Parts

Diaphragm

Field magnet

Moving coil (voice coil)

Figures representing a moving coil microphone


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Transformer

Step up transformer Step down transformer

Low volt AC High volt AC High volt AC Low Volt AC

Relation between the number of turns of coil of a transformer and induced emf

Moving coil loudspeaker

Main parts

Magnet

Voice coil

Diaphragm

Flow chart

Electrical signal from amplifier Voice coil diaphragm sound

RELATION BETWEEN VOLTAGE AND

CURRENT AND POWER OF A

TRANSFORMER

P=VxI

Power in primary = VP x IP

Power in secondary = VSX IS , In a transformer the

power in the secondary and primary is the same,

then VP x IP= VSX IS


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Schematic diagram of moving coil loudspeaker

Electric motor (DC motor)

Parts

Field magnet

Armature

Split ring commutator

Brushes

Motor converts electrical energy

Into Mechanicalenergy

Flemings Left hand rule

Stretch the thump, fore finger, and middle finger of the left hand, so that they are perpendicular to one

another. The fore finger represents the direction of the magnetic field, and the thumb indicates the

direction of the force and middle finger represent the direction of current .

FUNCTION

ELECTRIC SIGNAL IS CONVERTED

INTO SOUND SIGNAL

Sir John Ambrose Fleming

Sir John Ambrose FlemingFRS (29 November 184918

April 1945) was an Englishelectrical engineer andphysicist.He

is known for inventing the firstthermionic valve orvacuum tube,

thediode,later called theKontron in 1904. He is also famous for

theleft hand rule (for electric motors)
http://en.wikipedia.org/wiki/Fellow_of_the_Royal_Societyhttp://en.wikipedia.org/wiki/Electrical_engineerhttp://en.wikipedia.org/wiki/Physicisthttp://en.wikipedia.org/wiki/Thermionic_valvehttp://en.wikipedia.org/wiki/Vacuum_tubehttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Kenotronhttp://en.wikipedia.org/wiki/Fleming%27s_left_hand_rule_for_motorshttp://en.wikipedia.org/wiki/Fleming%27s_left_hand_rule_for_motorshttp://en.wikipedia.org/wiki/Kenotronhttp://en.wikipedia.org/wiki/Diodehttp://en.wikipedia.org/wiki/Vacuum_tubehttp://en.wikipedia.org/wiki/Thermionic_valvehttp://en.wikipedia.org/wiki/Physicisthttp://en.wikipedia.org/wiki/Electrical_engineerhttp://en.wikipedia.org/wiki/Fellow_of_the_Royal_Society


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Q23.To wind a step-down transformer to get an output of 10v by applying an input voltage of 250v, how many

turns are required in the secondary coil if the number of turns in the primary is 4500?

Q24. Complete the following table?

Name of device Working principle

DynamoMicro phone

Loud speaker

transformer

Q25. Initially 3v, 50Hz, AC is applied on the moving voice coil of a loudspeaker. After that a 3v DC is applied,

a. Which among these two will produce sound? Why?

b. What type of energy transformations occur in this device?

c. What arrangement is made to produce sound, when the voice coil vibrates in the moving loudspeaker?

d. Suppose you are given a circuit of loudspeaker, what changes can make that circuit into a microphone?

Q.26 AC is not suitable for electroplating.

a. Name the type of electricity used in the process electroplating?

b. Why Ac is not suitable for electroplating?

Q27 When a bicycle dynamo is examined by opening it, the following components were found .

It has a magnet and coil

There are no slip rings in it

a. .What type of electricity, we get from this dynamo?

b. Why slip rings were not used?

c. In which part emf is induced?

d. How can you increase the amount of emf obtained from this dynamo without changing its structure?

Q28. In a transformer NS : NP-3 : 5 , if VSis 300 v ,then what will be the value of VP?

Q29.Wat is the difference between a generator and an electric motor with respect to energy transformation?

Q30. You are given a long insulated copper wire, a galvanometer and a bar magnet.

a. How can you produce electromagnetic induction by using these?

b. How can you increase the strength of the induced current?

c. Write any two devices working on the principle of electromagnetic induction?


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Q31 Complete the table?

Characteristics of electric

current

Name of source Graphical representation

Flows in opposite directions with

continuous variations

Continuous increase and decrease

,but flows in the same direction

Flows in the same direction without

any change

Q32. Writethe following statement in the correct order and answer the given questions given below?

[Paper cone vibrates, Sound is produced, Electric signals reach the voice coil, and Voice coil vibrates]

a. Name the device?

b. Write the energy change in the device?

Q33.Bilal said .the electricity formed in the armature of a DC generator is actually AC

a. Is the statement true?

b. Write your opinion?

3. GENERATION AND DISTRIBUTION OF ELECTRIC POWER

Main points

POWER GENERATOR

SINGLE PHASE AND THREE PHASE GENERATOR

POWER TRANSMISSION

POWER DISTRIBUTION

TRANSMISSION LOSS

STAR CONNECTION

HOUSE HOILD WIRING

THREE PIN AND TWO PIN PLUG EARTHING

MEASUREMENT OF ELECTRICAL ENERGY

Power Station

The centre where electricity is generated for distribution

Mainly three types of power stations

Thermal power station Hydroelectric power station


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Output

[One end of the three phase line is connected together, this point is called neutral]

Power transmission and distribution

The process of sending electricity through wires from the generating station to the area where it is consumed is

known as power transmission.

Note:

Step up transformer are used at the substation near the power house

In other stage of distribution step down transformer is used

The voltages generated at the power station is 11 KV


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Problems related to the transmission of electricity to distant places

Voltage drop

Energy lose (Heat)

Q35. What are the problems related to the transmission of the electricity to the distant place? How can they be

minimized?

Ans ; it can be minimized by reducing the strength of electric current and by raising the voltage during

transmission.

(The heat developed in a conductor is directly proportional to the square of the current passing through it from

joules law)

Star connection

An arrangement of connecting one end each of the three phase coil at a common point is known as star

connection.

four lines come out of the distribution transformer meant for household and another purposes

Three lines come into the transformer


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Star connection

Note:

The potential difference between two phase line is 400v

Potential difference between one phase line and neutral line is 230v

One end each of the three phase coils will be connected together at a common point is called neutral

point, the voltage at that point will be zero

If a person standing on the earth touches the neutral line he does not get electric shock

House hold wiring

Parallel electric circuit is better for domestic wiring

Q 36 . What are the conveniences in connecting equipments in parallel?

Bulbs give maximum light when they are connected in parallel

Energy saved in parallel system since the required equipment alone can be switched on

We can control each equipment separately in a household circuit when it is connected in parallel

Total resistance of the circuit is minimized

Each appliance gets the same voltage

In parallel circuit ,if one electrical appliance stops working then all other appliances keep working

normally

Household wiring circuit


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1 kilowatt hour (1 unit) = 1000 x 3600 j = = 3600000 joule

Q37. Problem from text

Q38. Why we use very high voltage for transmitting electricity to distant places, why

Ans : power p= VI , when electricity is transmitted to distant place , there is a loss of energy due to heat. To

reduce this electric current should be minimum. So high voltage is used by decreasing the value of electric

current without changing the electric power.

Q39.Draw the graphic representation of a three phase AC?

Q40.The following picture shows three pin plugs

A a. What is the use of terminal E?

B b. To which part of the equipment is E to be connected?

C c.To which terminal are the fuse and the switch connected B or

C

Q41.

SI No Device Power

w

Time of

working

hour

Consumed energy in

kilowatt hour

1 Iron 750 0.5

2 Fan 60 2

3 Bulb 40 5

4 L.E.D 2 24

5 C.F.L 20 4


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Complete a domestic electric circuit of your own idea and label the names of devices used?

Q42. There are five 500 w bulbs and three 60w bulbs in a house circuit. They work for 5 hours daily. How many

units of electricity is consumed in the month of March?

Q43. Some details in a survey form attached with a project report of a student are given below:

Appliance power Total number Time in hours

Bulb 100 w 3 5

Bulb 60 w 5 5

Based on the survey calculate the total energy consumed per day in this house?

Ans : Total power 3 x100 + 5x 60 + =300+300 = 600W

Electrical energy used in one day =

Q44. 60 W power is obtained when a bulb is connected to 240 v. if the supply voltage is lowered to 180 v whatpower will be obtained?

Q45. If 0.01A current flows through a bulb working at 250V, how many hours are required to consume one unit

of electricity?

Ans v=230V, I=0.01 A,

P=V x I=250 x 0.01= 25 W

Time taken by the 25 W bulb to consume one unit of energy in hours= 1000/25 =40 hr

Q46. Find out the reason for the following.

a. Neutral line is earthed at different places?

b. The earth pin in a three pin plug is longer and thicker than other pins?

Ans . a, The neutral line will be maintained at zero potential by earthling at different points along its length

4. SOUNDMain Points

Sound

Transmission of sound

Characteristics of sound

Doppler effect

Resonance

Beats

Limit if audibility

Reflection of sound

Acoustics of building

Sound pollution


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Sound

Sound is a form of energy which makes as hear. Sound is produced by the vibration of the objects.Objects that

produce sound are called sources of sound.

Frequency of sound

It is the number of vibrations per second, and its unit is Hertz. [Sound changes according to change in

frequency. The frequency of sound waves is the same as that of the vibrating body which produecs sound.

The reason for the sound variation from different sources is due to the difference in their frequency.]

Natural frequency

Every vibrating objects has its own frequency, this frequency is called natural frequency. This natural frequency

does not change if it is allowed to vibrate freely.

Factors on which the frequency depends

Nature of the material

Thickness

Length tension

Transmission of sound

Sound needs a material medium like solid, liquid or gas to travel; the substance through which sound travels is

called a medium.

Dou you know!

The moon has no air or atmosphere at all. It is all vaccum on the surface of moon. Sound cannot be heard

directly on the surface of moon because there is no air on the moon to carry the sound waves.

Velocity of sound

Sound travels faster in solids than in liquids, because the molecules inside solid substance are packed tightly.

The speed of sound in liquids is comparatively slow. As the molecules in gases are loosely packed speed of

sound through gases is much slower.

Medium Velocity of sound m/s

Aluminum 6420

Iron 5950

Steel 5960

Water 1498

Air 340

Remember this sped =


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Sound waves are longitudinal waves

The distance between two nearest points in a wave which are in the same phase of vibration is called

the wavelength.

The distance travelled by the wave in one second is called velocity of the wave or the speed of the

wave

The maximum displacement from its mean position is called amplitude of the wave

Characteristics of sound

Loudness

Intensity of sound

Pitch

Timber or quality

1.Intensity of sound

Intensity of sound is the quantity of sound energy passed vertically through a unit surface in unit time.

According to the increase in the amplitude of vibrating object the intensity also increases.

2. Loudness

The intensity of sound produced in the ear is called loudness.

The relation between wavelength, frequency, and velocity of a wave is

Velocity =frequency x wavelength, V =f x

The intensity of sound is proportional to the square of the amplitude of the sound. The intensity of

sound is the amount of energy passing through unit area per second perpendicular to the direction of

propagation. Its unit is W/m2

Loudness is the measure of audibility produced by sound in a person. This is also called sound

pressure level. Its unit is decibel (db).it can be measured by an instrument called the decibel

meter

This depends on Intensity of sound, Frequency and Efficiency of the ear


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31CAPSULE PHYSICS

Resonance

When the natural frequency of the body undergoing forced vibration becomes equal to the frequency of the

impressed vibration, the body undergoing forced vibration will vibrate with greater amplitude, in this state the

two objects are said to be in resonance.

Beats

If two sound sources of slightly different frequencies are sounded together, a periodic rise and fall in intensity

will be heard, this phenomenon is known as beats

Limit of Audibility

Limit of Audibility depends on two factors

Intensity of sound

Frequency of sound

Normally a person can hear frequencies from 20 Hz to 20,000 Hz

Sound of frequency less than 20Hz are called infrasonic sounds.

Sound of frequency greater than 20 kHz are called ultrasonic sounds.

Dogs ,bats , dolphins can hear sounds above 20Hz

Rhinoceroses can hear sounds of frequencies 5Hz and above

Whales and elephants can produce and hear infrasonic sounds

Bats produce ultrasonic sounds having high frequency when they travel at night

Certain types of rats and butterflies also have the capacity of identifying the ultra sonic sound .Using

this capacity they escape from bats

Certain animals and birds have the capacity to identify the infrasonic sound produced before

earthquake.

Supersonic waves: waves whose speeds exceed the speed of sound in air

Subsonic waves: waves having speeds below the speed of sound in air


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32CAPSULE PHYSICS

Uses of Ultrasonic sounds

To record the function of the heart (echocardiograph)

To study the functioning of internal organs like liver kidney ,uterus ( Ultrasonography )

To crush small stones formed in the kidney

To measure of depth of oceans (SONARSound Navigation and Ranging)

For detecting flaws

For emulsification in industry

Reflection of sound

Sound can also be made to change its direction and bounce back when

It falls on hard surface.

Multiple Reflections

Multiple reflection of sound is the process in which sound waves bounces off obstacles and reflects many

times before reaching the destination. This is the phenomena that occur in a stethoscope. Sound waves reflect

through the tube many times before reaching the ears of the doctor.

A supersonic aircraft is anaircraft able to fly faster than thespeed of sound (Mach 1).Supersonic aircrafs were

developed in the second half of the twentieth century and have been used almost entirely for research and

military purposes. Only two,Concorde and theTupolev Tu-144,were ever designed for civil use as airliners.

The aerodynamics of supersonic flight is calledcompressible flow because of the compression associated with the

shock waves or "sonic boom" created by any object travelling faster than sound.

Persistence of hearing:

The sensation of hearing sound

produced by sound is retained for a

period of 1/10 second; this peculiarityof the ear is persistence of hearing.
http://en.wikipedia.org/wiki/Aircrafthttp://en.wikipedia.org/wiki/Speed_of_soundhttp://en.wikipedia.org/wiki/Supersonic_speedhttp://en.wikipedia.org/wiki/Concordehttp://en.wikipedia.org/wiki/Tupolev_Tu-144http://en.wikipedia.org/wiki/Compressible_flowhttp://en.wikipedia.org/wiki/Compressible_flowhttp://en.wikipedia.org/wiki/Tupolev_Tu-144http://en.wikipedia.org/wiki/Concordehttp://en.wikipedia.org/wiki/Supersonic_speedhttp://en.wikipedia.org/wiki/Speed_of_soundhttp://en.wikipedia.org/wiki/Aircraft


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Application of multiple reflection of sound

Used in stethoscope Megaphone and horns

Echo

Sound or sounds caused by the reflection of sound

waves from a surface back to the listener or Echo is the same sound heard again after sound is heard

Acoustics of buildings

Architectural acoustics is the science and engineering of achieving a good sound within a building and is a

branch of Acoustical engineering.

The factors to be taken into account while constructing an auditorium

Heavy curtains are put on the doors and windows to absorb sound and reduce reverberations

Carpets are put on the floor

Avoid curved walls

Panels made of sound absorbing materials are put on the walls and ceiling of big halls

Q .50. What are the possible effects of reflection of sound in a big hall?

Cannot hear the sound properly

The sound is heard repeatedly

The sweetness of music is lost Loudness is insufficient

Sound cannot be heard uniformly at all places in the hall

Q.51. what can be done to minimize the disadvantages due to these phenomena?

A large number of ventilators and windows are provided

Curtains having many folds are used

Walls are made rough

Presence of large number of audience increase the sound absorbing space

Q52. Write the ways to minimize sound pollution in town and note down your suggestions?

Plant trees on the road side

Obey the laws to control noise pollution

Avoid air horns and loudspeakers

Maintain automobiles in good condition

Q53 A small bomb explodes just below the water surface at a distance of 1500 m from a ship .Suppose a person

on the ship hears the sound of explosion

a. Which are the media through which the sound travels to reach the ship?

b. If the speed of sound in water is 1500m/s , how long will it take for this sound to reach the ship through

water?


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c. calculate the time the sound takes to travel the same distance through air ( speed of sound in air is 340 m/s)?

ans : a, air and water

b. speed = 1500m/s

Distance =1500 m

Time =?

Distance = Speed x time

Time =distance / speed

= 1500/1500= 1 s

c. speed = 340 m/s

Distance = 1500m

t = 1500/340 = 4.4 s

Q.54. Write the application of Doppler Effect?

To estimate the speed of submarine , aero plane , automobile, etc

To track the artificial satellite

To estimate velocity of rotation of star

This principle also used by the police to measure the speed of vehicles

Q.55 . A tuning fork produces sound waves of frequency 170Hz. If the speed of sound waves is 340 m/s , what

will be the wave length?

Ans : f = 170 Hz v = 340m/s = ?

V = f x

=

= =2 m

Q 56. What is the speed of a wave with frequency 256 Hz and wave length 2m?

f= 256 Hz = 2 m V =? V = f x , V =256 x 2 = 512 m/s

Tips

LOUDNESS is directly proportional to Squareof amplitude. LOUDNESS is directly proportional to surface area. LOOUDNESS increases with increase in density of medium. LOUDNESS is inversely proportional to square of distance. LOUDNESS is the measure of audibility produced by sound in a person It is also called sound pressure level Repeated reflection of sound is called reverberation


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Q 57 Ultra sonic sound: sonar - multiple reflection: -------------------&..............................

Ans stethoscope, horn

Q 58 The frequency of a given sound is 1.5K Hz. How many vibrations does it complete in one second?

F =

Number of vibration = frequency x time

= 1.5 x 1000 x 1

= 1500 vibrations

Q 59 Write any two differences between sound wave and light wave?

Ans

Sound Light

Medium required Medium not required

Velocity depends on temperature Velocity does not depend on

temperature

Q 60 Fill the box

Velocity m/s

Wavelength

Hz

w/m2

Intensity of sound

Period

Q 61 What are the effects of noise pollution?

Q 62 How can the noise pollution, be controlled in residential area?

Q63 Give some suggestion by which we can keep our ears healthy?

Q 64 Why dont we hear echoes in our ordinary surroundings?

Ans : Because the distance to hear echo should be more than 17 m

Q 65 Can we hear sound when we are on the surface of moon?

Q a tuning fork of frequency 512 Hz is excited and its stem is pressed on a table

a. Now what will be the frequency of vibration of the table?

Ans 512 Hz

b. What is the reason for increase in loudness?

Ans : surface area of the table is large

c. what is the phenomenon called ?

ans: Forced vibrations


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5. OPTICAL PHENOMENA

MAIN CONTENT

Composite light

Dispersion of light

Rainbow

Opaque and transparent objects

Newtons colure disc

Primary and secondary colours

Complementary colours

Scattering of light

The rising /setting sun and the sky

Colure of the sky

U-V and I-R rays

Composite light

Any light, which is composed of two or more colours . Eg: Sun light, torch light, candle light

Dispersion of light

The phenomenon of the splitting up of composite light into its components coloure is known as dispersion of

light.

Relation between wavelength and deviation of the

Colours ?

The colour which has lowest wavelength deviates most and with highest wavelength deviates least An array of constituent colours formed as a result of dispersion is the spectrum The component colours in the white light deviate at different rates according to their wavelength this is

the reason for dispersion

Dispersion of light can occur in water also Rainbow is formed as result of dispersion of light

Electromagnetic spectrum

Visible light is a part of the electromagnetic spectrum .There is other electromagnetic waves on both side of it.

They are: radio waves, infrared, visible light, ultraviolet, X ray & gamma rays


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Electromagnetic spectrum

Rainbow

It is formed by the dispersion of sunlight when it passes through rain drops. Rainbow is formed on the opposite

side of the sun.

Refraction of light in the water drop two times and due to total internal reflection, it split s into

component colours.

Violet undergoes maximum deviation and red undergoes minimum deviation. It is this spectrum that

we see as a rainbow

Rainbow is seen in the form of an arc:The line joining the centre of rainbow and the observer is theline of vision. Each coloured ray makes a definite angle with the line of vision (violet-40.80andred-

42.70). These angles cause rainbow to be seen in the form of an arc.

Colour of opaque objects

An opaque object reflects its colour, if it does not reflect any colour ,it appears as black

Black is not a colour , it is the absence of colour

If an opaque object reflects all colours it appears as white


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39CAPSULE PHYSICS

Secondary colour Component Primary colours

yellow Green +Red

Cyan Green + Blue

Magenta Blue +Red

Complementary Colours

The pair of colours combined with a primary colour to get white light.

Green + Magenta

Red + cyan White light

Blue + yellow

Scattering of light

Irregular and partial reflection of light during its passage through a medium .

The size of the particle increases, the rate of scattering increases. If the size of particle is greater than the wavelength of light then scattering is same for all colours.

Red colour (higher wavelength) occurs minimum scattering while Violet (lower wavelength) occurs

maximum scattering.

Colour of the sky-Blue, Deep sea appear blue, Colour of rising/ setting sun-Orange red, Colour of

accident signal-Red Smog season headlight colour-Yellow etc are explained on the basis of scattering

Q66 write down the reason for seeing the sun in red during sunrise and sunset?

Q67 why does deep sea appear blue?

Q68 The sky appears dark in the moon, what might be the reason?

Q69 Why does the sky appear blue?

Ultraviolet rays and Infrared rays

I-R rays which has more wavelenght than visible Light

UV rays which has least wavelength than visible light


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41CAPSULE PHYSICS

1.Name the rays that represent A and B?

2. Write any uses of the radiation B

Q 73 The figure shows a laser beam passing through a glass prism.

1. Which one is the correct figure?

Q74 Havent you made artificial rainbows?

1. Which is the colour seen on the inner edge?

2.What is meant by line of vision?

3. What is the reason for a rainbow appearing as an arc?

6. ELECTRONICS

MAIN CONTENT

Electronic devices

Semiconductors

Diode

Rectification

Transistors

Amplification

Integrated circuit

Introduction

By combining the two words, electrons and mechanics we get the word electronics. It is that field of science and

engineering, which deals with electron devices and their utilization.

Basic electronic functions

Resistor

Function: Regulating the current supply and necessary potential difference to the components. It causes energy

loss. The value is recorded directly and on it or using colour code. Unit: Ohm ()

Symbols:


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Inductor

Function: inductors are coils of conducting wire. The ability to resist the variation of electric current without

energy loss is the function of inductor. Unit: Henry (H)

Symbol

Capacitors

Function: Store electric charges and release them when necessary. Two parallel metallic plates and an

insulator (called dielectric) between the plates are major parts.

Eg: Paper, Ceramic, Polyester, Mica Capacitors (these are dielectrics used) Unit: Farad (F). Microfarad (f), &

Picofarad (Pf) are practical units

Symbols:

Capacitor opposes DC and passes AC

In paper capacitors paper is used as dielectric Capacitors which an electrolyte is used as a dielectric are electrolytic capacitors

Two type of electrolytic capacitors 1. Aluminum electrolytic capacitor & Tantallam electrolytic

capacitor

SEMICONDUCTORS

Substance can be classified as conductors, semiconductors& insulators based on their electrical conductivity

Substance

Semiconductors:The conductivity of semiconductors is higher than that of insulators, but lower than that of

conductors.

Semiconductors are classified in to two types

Intrinsic: Pure form, these are Insulator because the electron hole pairs are equal.

Extrinsic: Conductivity increases by doping with impurities.

Inductor

Conductoris an object or type

of material that permits the flow

of electric charges in one or more

directions

A semiconductoris a material

which has electrical

conductivity between that of a

conductor and insulator

An electrical insulatoris a

material whose internal electric

charges do not flow freely


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43CAPSULE PHYSICS

Extrinsic semiconductor is again classified in to two types.

n- type: Doped by donor impurity (Arsenic or Antimony) Majority: electrons.

p- type: Doped by acceptor impurity (Boron/Gallium/Indium) Majority: holes

Q75 .What is doping?

The process of adding some external substance into the semiconductor material to increase its conductivity is

called doping.

Q76 what is hole?

The vacancy of an electron which can behave as a positive charge is called a hole.

Diode

Pn junction diode is a semiconductor crystal in which one end is doped with p-type semiconductor and otherend with an n- type semiconductor

Diode on circuit

A Diode can be connected in two ways to an external voltage

Forward biasing

Reverse biasing


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44CAPSULE PHYSICS

Forward biasing

Pend of the diode is connected to the +ve pole and n-end to the negative pole of the a cell then the diode said

to be in Forward biasing

In forward biasing electric current flow through the diode

fig (a)

Forward biasing Reverse biasing

Reverse biasing

When p-end of the diode is connected to the negative pole and n-end is connected to the positive pole of the cell

the diode is said to be reverse biased

{Forward and reverse biasing of a diode shown in fig (a}

L.E.D [Light emitting diode]

A light-emitting diode (LED) is a two-leadsemiconductor light source that resembles a basicpn-junction diode,

except that an LED also emits light. The LED consists of a chip of semiconducting materialdoped with

impurities to create ap-n junction.As in other diodes, current flows easily from the p-side, oranode,to the n-

side, orcathode,but not in the reverse direction. Charge-carrierselectrons andholesflow into the junction

fromelectrodes with different voltages. When an electron meets a hole, it falls into a lowerenergy level and

releasesenergy in the form of aphoton.

Symbol of L.E.D

L.E.D

We have learned about more details of a diode, then one question. What are the uses of a Diode?

Rectification

What is rectification?

Rectification is the process of converting AC in to DC, a p-n junction diode acts as a rectifier.
http://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Pn-junctionhttp://en.wikipedia.org/wiki/Doping_(semiconductor)http://en.wikipedia.org/wiki/P-n_junctionhttp://en.wikipedia.org/wiki/Anodehttp://en.wikipedia.org/wiki/Cathodehttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Electron_holehttp://en.wikipedia.org/wiki/Electrodehttp://en.wikipedia.org/wiki/Energy_levelhttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Photonhttp://en.wikipedia.org/wiki/Photonhttp://en.wikipedia.org/wiki/Photonhttp://en.wikipedia.org/wiki/Energyhttp://en.wikipedia.org/wiki/Energy_levelhttp://en.wikipedia.org/wiki/Electrodehttp://en.wikipedia.org/wiki/Electron_holehttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Cathodehttp://en.wikipedia.org/wiki/Anodehttp://en.wikipedia.org/wiki/P-n_junctionhttp://en.wikipedia.org/wiki/Doping_(semiconductor)http://en.wikipedia.org/wiki/Pn-junctionhttp://en.wikipedia.org/wiki/Semiconductor


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Rectification is of two types

Half wave rectification

Full wave rectification

Half wave rectification

If only one half of a a-c is rectified, it is called half wave rectification .The circuit diagram is as shown in figure

below.

Working

When ac input voltage applied to the primary, a voltage is induced across the secondary. During the first half

cycle of ac input, first end of the secondary coil is positive and below end becomes negative ,then the diode

becomes forward biased. Current flows through the diode .During the negative half of the ac input the diode

become reverse biased, and no current flow through it.

Fullwave rectifier

In full wave rectifier, we get out put dc during the positive half and negative half of ac.

These are of two types

Centre-tap rectifier

Bridge rectifier

Centre-tap rectifier

The circuit diagram is as shown in fig. there are two diodes. Centre tap transformer is used


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Bridge rectifier

The circuit diagram is as shown in fig. there are four diodes in it.

Transistors

A semiconductor device with three connections, capable of amplification in addition to rectification .

A transistoris asemiconductor device used toamplify andswitchelectronic signals andelectrical

power.It is composed ofsemiconductor material with at least three terminals for connection to an external

circuit.

Transistor are classified in to two types

pnp

npn

A transistor has three terminals namely emitter (E), base (B), collector (C)

Note : emitter- base junction is forward biased and collector base junction is reverse biased

p-n-p and n-p-n Transistor

Transistor
http://en.wikipedia.org/wiki/Semiconductor_devicehttp://en.wikipedia.org/wiki/Electronic_amplifierhttp://en.wikipedia.org/wiki/Switchhttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Electrical_powerhttp://en.wikipedia.org/wiki/Electrical_powerhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Semiconductorhttp://en.wikipedia.org/wiki/Electrical_powerhttp://en.wikipedia.org/wiki/Electrical_powerhttp://en.wikipedia.org/wiki/Electrical_powerhttp://en.wikipedia.org/wiki/Electronicshttp://en.wikipedia.org/wiki/Switchhttp://en.wikipedia.org/wiki/Electronic_amplifierhttp://en.wikipedia.org/wiki/Semiconductor_device


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One more question for you! What is the function of a transistor?

Amplification

Amplification is the process of increasing the strength of electrical signal. pnp or npn transistor act as a

amplifier

Before amplification amplifier After amplification

Q77.Figure below shows a diode connected to the output of a transformer

a. Draw the graph of the emf obtained across the output?

b. Which function of diodeis utilized here ?

Q78 Observe the fig and answer the given questions?

a. Draw the graph of the emf obtained across A-B?

b. Write the principle used in this process?


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Q79 a. What are the electric components indicated by the symbols given below?.

b. What is the difference between them regarding electric conductivity?

Q80. Identify the symbols given below?

.

Q81. Which of the following diagrams represents a diode in forward biasing?

Q82 a , What is the function of an amplifier ?

b., Which is the component that performs this function in an amplifier?

Q83 Draw a symbol of p-n-p transistor?

Q84 Characteristics of a device are given below.

it can store electric charges

which consist of a dielectric

1. Name the device?

2. Write down its practical units?

Q85 The diode shown in the circuit has a resistance of 5 whenforward biased. If the maximum current thatcan be passed through the diode is 200Ma, what is the value of resistance R?

Ans : 200MA = 0.2A


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I =

0.2=

R+5 =6/0.2

R+5 =30

R=30-5=25

Q86 1.What is forward biasing?

2. Draw the circuit diagram of forward biasing of a p-n junction diode?

3. Mention its characteristics?

Q87. What happens to the conductivity of the following with increase in temperature?

1. Conductor, 2.Semiconductor, 3. Insulator

Q88 Draw the circuit diagram of full wave rectification?

Q89 What is meant by reverse biasing of diode? Mention its characteristics?

Q90 Observe the device given below.

.

1. Name the device?

2. Write the application of the given device?

3. Draw the symbol of the device?

Q91 .what is the electronic component depicted in the figure below?

Q92 what is the electric component depicted in the figure?


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7. OUR UNIVERSE

Main contents

Birth star

Constellation and ecliptic

Njattuvela

Sun

Stars

Galaxies

Big bang theory

Satellites

Birth star

The word birth staris related to the moon. The moon takes approximately 27 days to revolve round the earth

once. The moons orbit can be divided in to 27 segments, each of 13 degrees. These 27 segments are named on

the basis of the names of stars seen in each segment

The time taken by the moon to describe of its orbit is called an asterism or birth star

Constellation and ecliptic

The collections of stars are called constellations. There are 88 constellations.

ECLIPTIC is the orbit, along which the sun appears to move among the stars, the ecliptic is

divided into 12 equal parts. These are the 12 solar constellations. Earth

Constellation ecliptic

Celestial equator


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Each of the constellations is known by the shape of the stellar distribution in it. Every Malayalam month

corresponds to a particular rassi. There is a constellation for each rassi.

Malayalam Month: Explained on the basis of sun.

The sun takes nearly 30 days (365) to cross a constellation. This time is called Malayalam month. Every month

is named corresponds to the particular rassi. [Moon takes 2.25 days (27) to cross a constellation].

Njattuvela

It is the period of time (13-14 days) for which the sun appears together with an asterism (naal)

Sun

Energy production methodNuclear Fusion,

Energy distribution methodconvection and radiation.

Layers: Core, Radiative zone, Convective zone, Photosphere (layer of light), Chromospheres (layer ofcolour) and Corona (layer of heat).

Stars:

Colour of star depends on the temperature.

Colour of stars (Blue, White, Yellow, Orange, and Red)

According to descending order of temperature

Evolution of stars:


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Galaxy

A galaxy is a massive, gravitationally bound system consisting of stars, stellar remnants, an

interstellar medium of gas and dust, and dark matter, an important but poorly understood component.

It is a cluster of billions of stars and interstellar matter, bound by gravitational force.

According to its shape galaxies are Spiral, Elliptical and Irregular galaxy.

Milky Way (our galaxy) is a spiral type. Andromeda is the adjacent galaxy to Milky Way.

Big Bang theory

The Big Bangtheory is the prevailingcosmological model for the early development of the universe.

According to the theory, the Big Bang occurred approximately 13.798 0.037billion years ago,

which is thus considered as theage of the universe.

At this time, the universe was in an extremely hot and dense state and beganexpanding rapidly. Afterthe initial expansion, the universe cooled sufficiently to allow energy to be converted into

varioussubatomic particles, including protons, neutrons, andelectrons. Though simple atomic

nucleiformed within the first three minutes after the Big Bang, thousands of years passed before the

first electrically neutral atomsformed.The majority of atoms that were produced by the Big Bang

arehydrogen,along withhelium and traces oflithium.Giant clouds of these primordial elements later

coalesced throughgravity to formstars and galaxies, and theheavier elements were synthesized

eitherwithin stars orduring supernovae.

S.S.L.C MODEL QUESTION

Time: 1 hrs PHYSICS Total Score: 40

INSTRUCTIONS:

Fifteen minutes is given as cool off time.

This time is given to read and understand the questions well

For choice questions only one of them need to be answered

The score of each of question is given along with it.

1. Find the relation and fill the blanks

Control current without energy loss: .

Control current through energy loss: Resistor 1
http://en.wikipedia.org/wiki/Physical_cosmologyhttp://en.wikipedia.org/wiki/Planck_(spacecraft)#2013_data_releasehttp://en.wikipedia.org/wiki/1,000,000,000_(number)http://en.wikipedia.org/wiki/Age_of_the_universehttp://en.wikipedia.org/wiki/Metric_expansion_of_spacehttp://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalencehttp://en.wikipedia.org/wiki/Subatomic_particlehttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Big_bang_nucleosynthesishttp://en.wikipedia.org/wiki/Recombination_(cosmology)http://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Heliumhttp://en.wikipedia.org/wiki/Lithiumhttp://en.wikipedia.org/wiki/Gravityhttp://en.wikipedia.org/wiki/Starhttp://en.wikipedia.org/wiki/Periodic_tablehttp://en.wikipedia.org/wiki/Stellar_nucleosynthesishttp://en.wikipedia.org/wiki/Supernova_nucleosynthesishttp://en.wikipedia.org/wiki/Supernova_nucleosynthesishttp://en.wikipedia.org/wiki/Stellar_nucleosynthesishttp://en.wikipedia.org/wiki/Periodic_tablehttp://en.wikipedia.org/wiki/Starhttp://en.wikipedia.org/wiki/Gravityhttp://en.wikipedia.org/wiki/Lithiumhttp://en.wikipedia.org/wiki/Heliumhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Recombination_(cosmology)http://en.wikipedia.org/wiki/Big_bang_nucleosynthesishttp://en.wikipedia.org/wiki/Electronhttp://en.wikipedia.org/wiki/Subatomic_particlehttp://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalencehttp://en.wikipedia.org/wiki/Metric_expansion_of_spacehttp://en.wikipedia.org/wiki/Age_of_the_universehttp://en.wikipedia.org/wiki/1,000,000,000_(number)http://en.wikipedia.org/wiki/Planck_(spacecraft)#2013_data_releasehttp://en.wikipedia.org/wiki/Physical_cosmology


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2.Observe the figure

a) Which type of transformer is this? 1

b) Whether in primary or secondary of this transformer, thick copper wire is used and why? 3

3. Observe the figure

a) Which instrument is given in the figure 1b) Draw the output current graph. Note the features of the graph. 1c) Compare the currents in the external circuit and in the armature. 1d) Which element helps DC to available in the output? 1e) What type of current is generated if field magnet is rotated instead of the armature? 1

4.

.

a. Name the device? 1b. Write the application of the given device? 1

c. Draw the symbol of the device? 1

5. Havent you made artificial rainbows? 1

a. Which is the colour seen on the inner edge? 1

b. What is mean by line of vision? 1

c. What is the reason for a rainbow appearing as an arc? 2


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6. A

.

a.. Draw the graph of the emf obtained across A-B? 2

b. write the principle used in this process? 1

OR

6B A .Name the rays represent A and B? 1

B .Write any uses of the radiation B 2

V I B G Y O R

A B

7. Find out the reason for the following.

a. Neutral line is earthed at different places? 2

b. The earth pin in a three pin plug is longer and thicker than other pins? 2

8. When a bicycle dynamo is examined by opening it, the following factors were found out.

It has a magnet and coil

There are no slip rings in it

a. What type of electricity, we get from this dynamo? 1

b. Why slip rings were not used? 1

c. In which part emf is induced? 1

d. How can you increase the amount of emf obtained from this dynamo without changing its structure? 3

9 A B

25 W, 230v 30W, 230v

. A and B are two blubs

a. Which bulb has more resistance? 1


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b. If the bulb A works on 125v, calculate the heat produced in 10 minutes? 3

10. .Some material and there resistivity are given below

Silver-1.53, copper-1.68, iron-10, mercury-94

a. Which among iron and mercury is a better conductor? 1

B .Which material is the best conductor? Why? 2

11. If a current of Y ampere is passed through a conductor of X ohm resistance for a period of Z second,

a. Find the heat developed in the conductor? 1

b. When the current through a conductor is doubled, the heat developed in it will be increased

by? 1

Solved Problems & more questions

1. Calculte the heat developed when a potential difference of 230v is maintained across a

conductor of resistance 92 ohm for 14 minutes. What is the current in the circuit?

Ans

R =92 , t=14x60= 840 s, v = 230v

H = V2t/R

= =483000J

I= = =2.5A

2. What is the heat produced in 10 min in an electric heater connected to a 240v supply if 4A

current flows through it?

V= 240v, I= 4 A, t = 10x60= 600s

H=IVt= 240x4x600= 576000J

3. What is the time taken to produce 320000 J heat in a resistor of 200 ohm , if the current

passed is 2A?

I=2A, R=200 ohm, H=320000J

H=I2Rt, t =H/I

2R

t= =400s


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4. The area of cross section of a conductor is 2mm2and its resistance is 20.what will its

resistance be when its length is doubled?

Ans :

=

A = 2mm2, R=20 , l=l

=2 20

(1)

When its length is doubled, l=2l, then A=1mm2

Then the resistance is R

=1

2 (2)

Compare the two equations

1

2=

2 20

R= 2x2x20 =80

The length is doubled then its new resistance is 80

5.In a transformer Ns:Np =3:5 , if Vs= 300 V then what will be the value of Vp?

6.what is the difference between a generator and electric motor with respect to energy transformation?

7.You are given a long insulated copper wire , a galvanometer ,a bar magnet

a. how can you produce electromagnetic induction by using these ? Explain ?

b. How can you increase the strength of the induced current?

8.240 v ac is given to charge a battery

a. Which type of transformer is used to reduce 240v ac to 12 v supply?

b. if 4800 turns are in the primary of the transformer , then what is the number of turns in the

secondary ?

9.A wire of given material having length L and area of cross section A has a resistance of 4.

What would be the resistsnce of another wire of the same materials having length

2 and area of

cross section 2A?


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10 When the current through a conductor is doubled , then the heat developed in it will be

increased by.

Ans : h= I2xRx t

I=2I

Then H= (2I)2xRxt

= 4I2Rt

= 4 times of H

11.A negligilby small current is paassed through a wire of length 15m and uniform cross

section 6m2, and its resistance is measured to be 5. Find the resistivity of the material?

=

A= 6 m2, R=5, L=15m

=65

1= 30m

12. What is the resistance of 2m length of a nichrome wire, which has a radius of 0.33 mm.

Resistivity of nichrome is 1.5 m?

13. Find out the reason for the following?

1. Neutral line is earthed at different places?

Ans. The neutral line will be maintained at zero potential by earthing it at different points

along its length

2. The earth pin in a three pin plug is longer and thicker than the other pins?

Ans: the earth pin has low resistance because of its thickness. It gives perfect earthing.

Therefore the earth pin in a three pin plug is longer and thicker than the other pins.

14. In a long hall sound produced at one end is heard after one second again.

a. What is this phenomenon called?

b. what is the length of the hall if the velocity of sound is 345m/s?

ans a) Echo

b) 2d= v/t =345/1

d= 345/2=172.5m


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15. What is meant by energy crisis?

Increased need for energy and the decrease in the availability is the energy crisis

16. What is meant by calorific value?

The heat energy obtained when one kilogram of fuel is burn completely is its calorific value

and its unit is j/kg

17. Caloric value of hydrogen is 150j/kg and the calorific value of LPG is 55j/kg

a. Which one is a better fuel ? Why?

b. Which one will you select as a domestic fuel? Why?

Ans a. Hydrogen , its calorific value is greater than LPG

b. LPG, the rate of burning of His high. So there is a chance of explosion, it is difficult to

store. Because of these reasons LPG is chosen as domestic fuel.

18.A heater is labeled as 800W, 400v ?

a. What does this labeling mean?

b.What is the power of the device when it is given a potential difference of 200v ? What

is the current flowing through it?

C .If a potential difference of 100v is given to the heater, what will the power of the

instrument be?

Ans : a,. When the potential difference of the given device is 400v and its power is 800w

P=V2/R, R=V

2/P=

400400

800= 200

When V=200V

P=200200

200= 200

I=

=200

200= 1

C.V=100V

P=V2/R=

100100

20050.

I=

=100

200= 0.5


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19. A small bomb explodes just below the water surface at a distance of 1500m from a ship. Suppose

a person on the ship hears the sound of the explosion

a.Which are the media through which the sound travels to reach the ship?

Ans : water and air

b.Iif the speed of sound in water is 1500 m/s , how long will it for this sound to reach the ship

through water?

Ans: speed =

Time=

=

1500

1500= 1

c. Calculate the time the sound takes to travel the same distance through air ,speed of sound in air is

340m/s

ans: Time=

=

1500

340= 4

Equations

4. t=H/I2R unit of heat =Joule (j)

5. R = H/I2t

6. I2 = H/Rt or I=

7. P =VI8. P= I2R

9. P = V2/R

10. = ,Its unit is ohmmeter ( m)

11. Effective resistance in series R=R1+R2+R3+

12. Effective resistance in parallel = + +.

1. H = I2Rt

2. H = V2t /R

3. H =VIt


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13.

.

14. Energy consumed in kilowatt hour =

Physics Quiz

Test how much you know about physics by trying our fun physics quiz. Theres a range of questionsabout topics such as energy, motion, friction, magnets, force, gravity and light.

Take the challenge and pick up some interesting physics facts and trivia along the way. Once youvefinished with the questions, check your answers to see how much you got right.

1. When light bends as it enters a different medium .This e process is known as what?

2. A magnifying glass is what type of lens?

3. Electric resistance is typically measured in what units?

4. A person who studies physics is known as a?

5. Metals expand when heated and what happens when cooled?

6. What is the first name of the famous scientist who gave us Newtons three laws of motion?

7. Which computer technology is used to train pilots when wanting to copy the experience of flying an aircraft?

8. Electric power is typically measured in what units?

9. The most recognized model of how the universe begun is known as -----------

10. The Hubble Space Telescope is named after whom?

11. The wire inside an electric bulb is known as -----------

12. Theoretical physicist James Maxwell was born in what country?

13. Infrared light has a wavelength that is too long or short to be visible for humans?


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61CAPSULE PHYSICS

14. What kind of eclipse do we have when the moon is between the sun and the earth?

15. True or false? Iron is attracted by magnets.

16. What is the earths primary source of energy?

17. Conductors have a high or low resistance?

18. Electric current is typically measured in what units?

19. What scientist is well known for his theory of relativity?

20. Earth is located in which galaxy?

Physics Quiz Answers

1. Refraction 2. Convex 3. Ohms 4. Physicist

5. Contract 6. Isaac 7. A flight simulator 8. Watts

9. Big bang 10. Edwin Hubble 11. Filament 12. Scotland

13. Long 14. A solar eclipse 15. True 16. The sun

17. Low 18. Amperes 19. Albert Einstein 20. The Milky Way galaxy

Thank you


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Std. 10 Physics Capsule by Alif Muhammed

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