Name: Chapter 14 Light - A. Hammond Biologyahammondbiology.weebly.com/uploads/3/7/6/6/... · (c)...
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Chapter 14 Light Name: ________________________ Class: ________________________ Date: ________________________ Time: 143 minutes Marks: 143 marks Comments: Page 1 of 53
Transcript of Name: Chapter 14 Light - A. Hammond Biologyahammondbiology.weebly.com/uploads/3/7/6/6/... · (c)...
Chapter 14 Light
Name: ________________________
Class: ________________________
Date: ________________________
Time: 143 minutes
Marks: 143 marks
Comments:
Page 1 of 53
A person can see an image of himself in a tall plane mirror.
The diagram shows how the person can see his hat.
(a) Which point, A, B or C, shows the position of the image of his hat?
Write the correct answer, A, B or C, in the box.
(1)
1
(b) On the diagram, use a ruler to draw a light ray to show how the person can see his shoe.
(3)
(c) Which one of the words in the box is used to describe the image formed by a plane mirror?
Draw a ring around the correct answer.
imaginary real virtual
(1)
(Total 5 marks)
(a) The diagram shows two parallel rays of light, a lens and its axis.
(i) Complete the diagram to show what happens to the rays.
(2)
2
(ii) Name the point where the rays come together.
...........................................................................................................................
(1)
Page 2 of 53
(iii) What word can be used to describe this type of lens?
...........................................................................................................................
(1)
(b) The diagram shows two parallel rays of light, a lens and its axis.
(i) Which point A, B, C, D or E shows the focal point for this diagram?
Point ..................
(1)
(ii) Explain your answer to part (b)(i).
...........................................................................................................................
...........................................................................................................................
(1)
(iii) What word can be used to describe this type of lens?
...........................................................................................................................
(1)
(c) Complete the following three sentences by crossing out the two lines in each box whichare wrong
film
In a camera a converging lens is used to produce an image on a lens .
screen
The image is
larger than
smaller than
the same size as
the object.
Compared to the distance of the image from the lens, the object is
further away from
nearer to
the same distance from
the lens.
(3)
Page 3 of 53
(d) Explain the difference between a real image and a virtual image.
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(3)
(Total 13 marks)
The ray diagram shows the image formed by a concave mirror.
Use the equation in the box to calculate the magnification.
Show clearly how you work out your answer.
........................................................................................................................
........................................................................................................................
Magnification = ...............................................
(Total 2 marks)
3
Page 4 of 53
A student investigated the refraction of light as it passed out of a clear plastic block into the air.
Diagram 1 shows the apparatus the student used.
Diagram 1
(a) The angle i is the angle of incidence.
Use the letter r to mark the angle of refraction on Diagram 1.
(1)
4
(b) The student measured the angle of refraction for different angles of incidence.The results are shown in the graph.
Angle of incidence in degrees
(i) One of the results seems to be anomalous.
Draw a ring around the anomalous data point on the graph.
(1)
Page 5 of 53
(ii) The student did measure the angles of incidence accurately.
What is likely to have caused the anomalous result?
...............................................................................................................
...............................................................................................................
(1)
(iii) What conclusion can the student make from the results shown in the graph?
Draw a ring around the correct answer to complete each sentence.
less than
The angle of refraction is equal to the angle of incidence.
greater than
(1)
(c) Light travelling from water into air is refracted in the same way as when light travels fromplastic into air.
Diagram 2 shows a large bottle, filled with water. The bottle is made from clear plastic.
Draw on Diagram 2 the path of the light ray as it passes out of the bottle into the air.
Diagram 2
(2)
Page 6 of 53
(d) In some countries, people are too poor to pay for electricity. Some people living in smallhouses with no natural light use bottles filled with water as a sort of light bulb.
The bottles are fitted into small holes in the roof of the house. Sunlight goes into the bottleof water. When the light leaves the bottle, the light is refracted, causing sunlight to spreadinto the room.
Diagram 3
(i) What is likely to be the most important outcome of using this simple device to providelight?
Tick ( ) one box.
People will have enough light to work inside their homes.
Fewer plastic bottles will be thrown into rubbish tips.
Plastic bottles will increase in value.
(1)
(ii) Suggest one disadvantage of using this device compared with using a light bulb.
...............................................................................................................
...............................................................................................................
...............................................................................................................
(1)
(Total 8 marks)
Page 7 of 53
(a) Figure 1 shows a ray of light entering a glass block.
(i) The angle of incidence in Figure 1 is labelled with the letter i.
On Figure 1, use the letter r to label the angle of refraction.
(1)
5
(ii) Figure 2 shows the protractor used to measure angles i and r.
What is the resolution of the protractor?
Tick ( ) one box.
1 degree 5 degrees 10 degrees
(1)
Page 8 of 53
(iii) The table shows calculated values for angle i and angle r from an investigation.
Calculated values
sin i = 0.80
sin r = 0.50
Use the values from the table to calculate the refractive index of the glass.
Use the correct equation from the Physics Equations Sheet.
...............................................................................................................
...............................................................................................................
...............................................................................................................
Refractive index = ..................................
(2)
(b) The diagrams below show a ray of light moving through glass.
Which diagram correctly shows what happens when the ray of light strikes the surface ofthe glass at the critical angle?
Tick ( ) one box.
(1)
Page 9 of 53
(c) A concave (diverging) lens is fitted into a door to make a security spyhole.
Figure 3 shows how this lens produces an image.
(i) State one word to describe the nature of the image in Figure 3.
.............................................................
(1)
(ii) Use data from Figure 3 to calculate the magnification of the image.
Use the correct equation from the Physics Equations Sheet.
...............................................................................................................
...............................................................................................................
...............................................................................................................
Magnification = ....................................................
(2)
Page 10 of 53
(iii) What is another use for a concave lens?
Tick ( ) one box.
A magnifying glass
Correcting short sight
To focus an image in a camera
(1)
(Total 9 marks)
The diagram shows a lens being used as a magnifying glass.
(a) (i) What type of lens is shown in the diagram?
Draw a circle around your answer.
concave converging diverging
(1)
6
Page 11 of 53
(ii) Use the equation in the box to calculate the magnification produced by the lens.
The object and image in the diagram have been drawn to full size.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
Magnification = ........................................
(2)
(b) The diagram shows how the image changes when the object has been moved closer to thelens.
Complete the following sentence by drawing a ring around the correct line in the box.
increases
Moving the object closer to the lens does not change the magnification produced
decreases
by the lens.
(1)
(Total 4 marks)
Page 12 of 53
The diagram shows a periscope being used to see over the heads of a crowd of people.
The periscope has been made using two plane mirrors.
(a) Using a ruler, complete the diagram to show how the second ray of light from a distantobject reaches the person’s eye.
(2)
7
(b) How big is the image produced by the periscope compared to the size of the object?
........................................................................................................................
(1)
(Total 3 marks)
Page 13 of 53
A puppy can see an image of himself in a plane mirror.
8
The diagram shows how the puppy can see his disc.
(a) On the diagram, use a ruler to draw a ray to show how the puppy can see the top of hisear, which is marked as T.
(3)
(b) What is a plane mirror?
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 4 marks)
The ray diagram shows a converging lens being used as a magnifying glass.The diagram has been drawn to scale.9
Page 14 of 53
(a) What name is given to the type of lens used as a magnifying glass?
........................................................................................................................
(1)
(b) Calculate the magnification produced by the lens.
Write down the equation you use, and then show clearly how you work out your answer.
........................................................................................................................
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Magnification = .....................................
(2)
(c) Describe the image produced by a magnifying glass.
........................................................................................................................
........................................................................................................................
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(3)
(Total 6 marks)
(a) The diagram shows a ray of light being reflected by a plane mirror.
Which of the angles, a, b, c or d, is:
the angle of incidence;
the angle of reflection?
(2)
10
Page 15 of 53
(b) The diagram shows a road junction seen from above.
A mirror placed at the side of the road allows the driver of car X to see car Y.
Using the same mirror symbol given in part (a), draw a plane mirror to show how it shouldbe placed so that the driver of car X can see car Y.
(2)
(Total 4 marks)
A student investigates how the magnification of an object changes at different distances from aconverging lens.
The diagram shows an object at distance d from a converging lens.
(a) (i) The height of the object and the height of its image are drawn to scale.
Use the equation in the box to calculate the magnification produced by the lensshown in the diagram.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
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Magnification = ............................................................
(2)
11
Page 16 of 53
(ii) The points F are at equal distances on either side of the centre of the lens.
State the name of these points.
...............................................................................................................
(1)
(iii) Explain how you can tell, from the diagram, that the image is virtual.
...............................................................................................................
...............................................................................................................
(1)
(b) The student now uses a different converging lens. He places the object between the lensand point F on the left.
The table shows the set of results that he gets for the distance d and for the magnificationproduced.
Distance dmeasured in cm
Magnification
5 1.2
10 1.5
15 2.0
20 3.0
25 6.0
His friend looks at the table and observes that when the distance doubles from 10 cm to 20cm, the magnification doubles from 1.5 to 3.0.
His friend’s conclusion is that:
The magnification is directly proportional to the distance of the object from the lens.
His friend’s observation is correct but his friend’s conclusion is not correct.
(i) Explain, with an example, why his friend’s conclusion is not correct.
...............................................................................................................
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...............................................................................................................
...............................................................................................................
(2)
Page 17 of 53
(ii) Write a correct conclusion.
...............................................................................................................
...............................................................................................................
(1)
(iii) The maximum range of measurements for d is from the centre of the lens to F on theleft.
The student cannot make a correct conclusion outside this range.
Explain why.
...............................................................................................................
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(1)
(Total 8 marks)
(a) Light waves transfer energy.
(i) Complete the following sentence.
The oscillations producing a light wave are ..................................................................
to the direction of the energy transfer by the light wave.
(1)
12
(ii) The apparatus in the diagram shows that light waves transfer energy.
Describe how switching the desk lamp on and off shows that light waves transferenergy.
You do not need to describe the energy transfers.
...............................................................................................................
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...............................................................................................................
...............................................................................................................
(2)
Page 18 of 53
(b) A student holds a wrist watch in front of a plane mirror. The student can see an image ofthe wrist watch in the mirror.
The diagram shows the position of the wrist watch and the mirror.
Draw a ray diagram showing how the image of the wrist watch is formed.
Mark the position of the image.
(4)
(c) The image of the wrist watch seen by the student is virtual.
What is a virtual image?
........................................................................................................................
........................................................................................................................
(1)
(Total 8 marks)
Page 19 of 53
A student investigates how the magnification of an object changes at different distances from aconverging lens.The diagram shows an object at distance d from a converging lens.
(a) (i) The height of the object and the height of its image are drawn to scale.
Use the equation in the box to calculate the magnification produced by the lensshown in the diagram.
magnification =
Show clearly how you work out your answer.
...............................................................................................................
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Magnification = ..................................................
(2)
13
(ii) The points F are at equal distances on either side of the centre of the lens.
State the name of these points.
...............................................................................................................
(1)
(iii) Explain how you can tell, from the diagram, that the image is virtual.
...............................................................................................................
...............................................................................................................
(1)
Page 20 of 53
(b) The student now uses a different converging lens. He places the object between the lensand the point F on the left.
The table shows the set of results that he gets for the distance d and for the magnificationproduced.
Distance d
measured in cmMagnification
5 1.2
10 1.5
15 2.0
20 3.0
25 6.0
His friend looks at the table and observes that when the distance doubles from 10 cm to 20cm, the magnification doubles from 1.5 to 3.0.
His friend’s conclusion is that:
The magnification is directly proportional to the distance of the object from the lens.
His friend’s observation is correct.
His friend’s conclusion is wrong.
(i) Explain using data from the table why his friend’s conclusion is wrong.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(ii) Write a correct conclusion.
...............................................................................................................
...............................................................................................................
(1)
Page 21 of 53
(iii) The maximum range of measurements for d is from the centre of the lens to F on theleft.
The student cannot make a correct conclusion outside this range.
Explain why.
...............................................................................................................
...............................................................................................................
(1)
(Total 8 marks)
(a) Figure 1 shows a diagram of a human eye.
Label the parts A and B on Figure 1.
(2)
14
(b) State the function of the iris.
........................................................................................................................
........................................................................................................................
(1)
Page 22 of 53
(c) Figure 2 shows light rays travelling into the human eye.
(i) Give the name of the defect of vision shown in Figure 2.
...............................................................................................................
(1)
(ii) A concave (diverging) lens can be used to correct the defect of vision shown inFigure 2.
Complete the ray diagram in Figure 3 to show how a concave lens produces animage of the object.
Use an arrow to represent the image.
(3)
Page 23 of 53
(d) It is important that muscles can change the power of the lens in the eye. State why.
........................................................................................................................
(1)
(e) The ‘power range’ of an eye lens is the difference between the maximum and minimumpower of the lens.
Figure 4 shows how the power range of an eye lens changes with age.
(i) Use data from Figure 4 to calculate the maximum change that can happen to thefocal length of the eye lens for a 60-year-old person.
Use the correct equation from the Physics Equations Sheet.
Give the unit.
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Maximum change in focal length = ................................... unit .............
(2)
Page 24 of 53
(ii) Compare the change in power range of the eye lens between the ages of 10 and 30with that between the ages of 50 and 70.
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(3)
(iii) Use Figure 4 to suggest the power range of the eye lens for a 90-year-old person.
Power range = ............................................................ dioptres
(1)
(Total 14 marks)
Figure 1 shows how a ray of light from a laser travels along an optical fibre.
Figure 1
(a) Why does the ray of light stay within the optical fibre?
........................................................................................................................
........................................................................................................................
(1)
15
(b) The material used to make the optical fibre has a refractive index of 1.50.
Calculate the critical angle of this material.
Use the correct equation from the Physics Equations Sheet.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Critical angle = .................................................. degrees
(2)
Page 25 of 53
(c) Different wavelengths of light can be used to transmit information along optical fibres.
Figure 2 shows how the percentage of incident light transmitted through a fibre varies withthe wavelength of light and the length of the fibre.
Figure 2
Wavelength × 10−7 metres
Compare the percentages of incident light transmitted through the two different fibres overthe range of wavelengths shown.
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(3)
(Total 6 marks)
Page 26 of 53
(a) The diagram shows a converging lens being used as a magnifying glass.
(i) On the diagram, use a ruler to draw two rays from the top of the object which showhow and where the image is formed. Represent the image by an arrow drawn at thecorrect position.
(3)
16
(ii) Use the equation in the box to calculate the magnification produced by the lens.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
Magnification = ........................................
(2)
Page 27 of 53
(b) A camera also uses a converging lens to form an image.
Describe how the image formed by the lens in a camera is different from the image formedby a lens used as a magnifying glass.
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(2)
(Total 7 marks)
The diagram shows a ray of light passing through a diverging lens.
17
Page 28 of 53
(a) Use the information in the diagram to calculate the refractive index of the plastic used tomake the lens.
Write down the equation you use, and then show clearly how you work out your answer.
........................................................................................................................
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........................................................................................................................
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........................................................................................................................
........................................................................................................................
Refractive index = ..................................
(2)
(b) The focal length of the lens is 5 cm. A student looking through the lens seesthe image of a pin.
Complete the ray diagram below to show how the image of the pin is formed.
(3)
(Total 5 marks)
Page 29 of 53
A student investigated the refraction of light as it passes into and out of a clear plastic block.
Diagram 1 shows the apparatus the student used.
Diagram 1
(a) Diagram 2 shows the same apparatus.
Use a ruler to draw on Diagram 2 the path of the light ray.
Diagram 2
(2)
18
Page 30 of 53
(b) The student measured the angle of refraction (r) for different angles of incidence (i) for lightentering the plastic block.
The results are shown in Graph 1.
Angle of incidence (i) in degrees
(i) What two conclusions can be made about the relationship between the angle ofincidence and the angle of refraction from Graph 1?
1 ............................................................................................................
...............................................................................................................
2 .............................................................................................................
................................................................................................................
(2)
Page 31 of 53
(ii) Graph 2 shows the student’s results for light passing from air into plastic. The graphalso shows the results for light passing from air into water.
Angle of incidence (i) in degrees
How does the refraction of light passing from air into water compare to the refractionof light passing from air into plastic?
...............................................................................................................
...............................................................................................................
(1)
Page 32 of 53
(c) In some countries people are too poor to pay for electricity. Some people living in smallhouses with no natural light are using bottles filled with water instead of light bulbs.
The bottles are fitted into small holes in the roof of the house. Sunlight refracts as it passesinto and out of the bottle, causing light to spread into the room. This simple device givesabout the same amount of light as a 50 W light bulb.
Diagram 3
(i) Suggest one way this simple device can help improve the lives of the people using it.
...............................................................................................................
...............................................................................................................
(1)
(ii) The increasing use of energy resources to generate electricity within developedcountries has ethical implications.
Suggest one ethical implication.
...............................................................................................................
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(1)
(Total 7 marks)
When glass is placed in a liquid of the same refractive index, the glass seems to disappear. Thismethod can be used to determine the refractive index of small pieces of glass.19
Page 33 of 53
(a) The refractive index of some types of glass and some liquids is given in the table.
Type of glassRefractive
index Liquid
Refractiveindex
Bakeware glass 1.47 Methanol 1.33
Car headlight glass 1.48 Water 1.33
Window glass 1.50 Alcohol 1.37
Bottle glass 1.52 Olive oil 1.47
Spectacle glass 1.54 Castor oil 1.48
Lead glass 1.62 Cinnamon oil 1.60
(i) Use information from the table to give an example of a type of glass and a liquidwhere the glass would seem to disappear.
Type of glass .................................................................
Liquid .................................................................
(1)
(ii) What is the range of refractive index of the liquids in the table?
From ........................................ to ........................................ .
(1)
(iii) Which type of glass has a refractive index outside the range for the liquids?
................................................................................................................
(1)
(b) The diagram shows a ray of light travelling from air into glass.
(i) What is the name given to the dashed line?
................................................................................................................
(1)
Page 34 of 53
(ii) Draw, on the diagram, the letter i to label the angle of incidence.
(1)
(iii) Draw, on the diagram, the letter r to label the angle of refraction.
(1)
(i) The value of i is 46° and the value of r is 29°.
Calculate the refractive index of the glass.
Use the correct equation from Section B of the Physics Equations Sheet.
................................................................................................................
................................................................................................................
Refractive index = ........................................
(3)
(ii) Look at the table in part (a).
Name a type of glass that could have been used in part (b).
................................................................................................................
(1)
(Total 10 marks)
Light changes direction as it passes from one medium to another.
(a) Use the correct answer from the box to complete the sentence.
diffraction reflection refraction
The change of direction when light passes from one medium to another is
called ......................................................... .
(1)
20
(b) Draw a ring around the correct answer to complete the sentence.
When light passes from air into a glass block, it changes
direction
away from the normal.
towards the normal.
to always travel along the normal.
(1)
Page 35 of 53
(c) Diagram 1 shows light rays entering and passing through a lens.
Diagram 1
(i) Which type of lens is shown in Diagram 1?
Draw a ring around the correct answer.
concave convex diverging
(1)
(ii) In Diagram 1, what is the point X called?
................................................................................................................
(1)
(d) A lens acts like a number of prisms.
Diagram 2 shows two parallel rays of light entering and passing through prism A and prismC.
Diagram 2
Draw a third parallel ray entering and passing through prism B.
(4)
(e) What two factors determine the focal length of a lens?
1 .....................................................................................................................
2 .....................................................................................................................
(2)
Page 36 of 53
(f) A converging lens has a focal length of 20 cm.
Calculate the power, in dioptre, of the lens.
Use the correct equation from Section B of the Physics Equations Sheet.
.........................................................................................................................
.........................................................................................................................
Power of the lens = .................................... dioptre
(2)
(Total 12 marks)
Page 37 of 53
Mark schemes
(a) C11
(b) reflection at the mirror of ray from shoe to person’s eye
may be drawn freehand1
angle of incidence = angle of reflection
judged by eyea ruler must have been used
1
arrow to show correct direction on either incident or reflected ray
only one arrow needed but if more drawn must be no contradiction
both incident and reflected ray must be shown1
(c) virtual1
[5]
(a) (i) rays continued to meet on the right hand side of the lens and beyond
must be straight lines from the right hand side of the lensignore details through the lensallow if no arrows
1
meet exactly on the axis
negate mark if contradictory arrow(s) addeddo not need to go beyond the focus for this mark
1
2
(ii) (principal) focus
or focal (point)1
(iii) converging
or convex1
(b) (i) A1
Page 38 of 53
(ii) rays seem to come from this point
or words to this effector shows this on the diagram
1
(iii) diverging
or concave1
(c) film
accept any unambiguous method of showing the correct response1
smaller than1
further away from1
(d) any three from:
• real image can be put on a screen
allow film
• virtual image cannot be put on a screen / film
• virtual image is imaginary
• real image is formed where (real) rays cross / converge
allow real image has light travelling through it
• virtual image is where virtual / imaginary rays (seem to) come from
or virtual image is where rays seem to come from
• virtual image formed where virtual rays intersect / cross3
[13]
1.4
allow 1 mark for correct substitution
ie 14 ÷ 10
or
28 ÷ 20
[2]
3
(a) angle of refraction correctly identified
accept any correct indication1
4
(b) (i) result at i = 25° identified1
Page 39 of 53
(ii) measuring angle of refraction incorrectly
accept any practical suggestion that would lead to the angle r beingincorrect
eg placing the protractor in the wrong place
not marking the refracted ray correctly / accurately / ray box hasbeen moved
do not accept measured angle i and angle r incorrectlydo not accept plotted incorrectly
1
(iii) greater than1
(c) shown refracting out of the bottle with angle of refraction larger than angle ofincidence
allow 1 mark for refraction shown on correct side of normal withangle of refraction smaller than angle of incidence
2
(d) (i) People will have enough light to work inside their homes1
(ii) accept any sensible suggestion
do not accept roof leaks
eg does not work at nightno control over light cannot switch on and off
eg cannot control brightness1
[8]
Page 40 of 53
(a) (i)
1
(ii) 1 degree1
5
(iii) 1.6
allow 1 mark for correct substitution, ie 0.80 / 0.5 provided nosubsequent step shown
working showing 1.59(9…..) scores zero2
(b) 2nd diagram ticked
1
(c) (i) any one correct description:• upright• virtual• diminished.
treat multiple words as a list1
(ii) 0.25
allow 1 mark for correct substitution, ie 1 / 4 or 5 / 20 provided nosubsequent step shown
ignore any unit2
(iii) Correcting short sight1
[9]
(a) (i) converging16
Page 41 of 53
(ii) (x) 2
allow 1 mark for correct substitution
ie 10/5 or 20/10 or 2/1
ignore any units2
(b) decreases1
[4]
(a) reflection shown at both mirrors17
ray parallel to given ray
judge by eye1
(b) same size1
[3]
(a) reflection at the mirror of ray from tip of real puppy’s ear to real puppy’s eye (1)
may be drawn freehand
accurate (1)
ruler must have been used and the reflected ray is an extension ofthe straight line from point virtual ear however the virtual part of theline need not be shown
8
arrow to show correct direction (1)
only one arrow needs to be shown but there must be nocontradiction
example of (3) mark response
3
(b) flat
accept ‘it’s not curved/bent’
accept ‘it’s straight’1
[4]
(a) converging
accept convex1
9
Page 42 of 53
(b) 3
allow 1 mark for substitution into the correct equation
2
ie
(c) bigger
accept magnified1
upright1
virtual1
[6]
(a) b1
c1
correct order only
10
(b) mirror opposite road junction1
mirror facing correct way, angle correct
judged by eye1
[4]
(a) (i) answer in the range 3.0 ↔ 3.1 inclusiveaccept for 1
3.6 ÷ 1.2 or 3.7 ÷ 1.2
or 36 ÷ 12 or 37 ÷ 12
or 18 ÷ 6 or 18.5 ÷ 6
or 10.2 ÷ 3.4 or 102 ÷ 34
or answer in the range but with a unit eg 3 cm2
11
(ii) (principal) focus / focal (point(s)) / foci / focus
accept ‘focusses’
accept focals
do not accept focal length1
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(iii) at the intersection of virtual / imaginary rays
or ‘where virtual / imaginary rays cross’
or the rays of (real) light do not cross
or the image on the same side (of the lens) as the object
or the image is drawn as a dotted line
or the image is upright
do not accept ‘cannot be put on a screen’
do not accept any response which refers to reflected rays1
(b) (i) another correct observation about relationship between values of d (1)
(but) not the same relationship between correspondingvalues for magnification (1)
example
15 is three times bigger than 5 but
2.0 is not three times bigger than 1.22
(ii) when the distance / d increases the magnification increases
or the converse
accept ‘there is a (strong) positive correlation’
do not accept any response in terms of proportion / inverseproportion
1
(iii) (student has) no evidence (outside this range)
accept data / results / facts for ‘evidence’1
[8]
(a) (i) perpendicular
accept correct description 11
12
(ii) light off – no / slow rotation1
light on – fast(er) rotation
accept starts rotating
ignore references to energy transfers1
(b) one ray drawn from wrist watch and reflected by mirror
accept solid or dashed lines1
two rays drawn from wrist watch and reflected by mirror with i = r for both rays
judge angles by eye1
one ray traced back behind mirror
accept solid or dashed lines1
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image in correct position
judged by eye
accept image marked where two reflected rays traced back crossbehind the mirror
1
(c) cannot be formed on a screen
accept image formed behind the mirror
or
rays of light seem to come from it but do not pass through it1
[8]
(a) (i) answer in the range 3.0 ↔ 3.1 inclusiveaccept for 1 mark
3.6 ÷ 1.2 or 3.7 ÷ 1.2
or 36 ÷ 12 or 37 ÷ 12
or 18 ÷ 6 or 18.5 ÷ 6
or 10.2 ÷ 3.4 or 102 ÷ 34
or answer in the range but with a unit eg 3 cm2
13
(ii) (principal) focus / focal (point(s)) / foci / focus
accept ‘focusses’
accept focals
do not accept focal length1
(iii) at the intersection of virtual / imaginary rays
or ‘where virtual / imaginary rays cross’
or the rays of (real) light do not cross
or the image on the same side (of the lens) as the object
or the image is drawn as a dotted line
or the image is upright
do not accept ‘cannot be put on a screen’
do not accept any response which refers to reflected rays1
(b) (i) another correct observation about relationship between values of d
example
15 is three times bigger than 5 but1
(but) not the relationship between corresponding values for magnification
2.0 is not three times bigger than 1.21
Page 45 of 53
(ii) when the distance / d increases the magnification increases
or the converse
accept ‘there is a positive correlation’
do not accept any response in terms of proportion / inverseproportion
1
(iii) (student has) no evidence (outside this range)
accept data / results / facts for ‘evidence’1
[8]
(a) A = suspensory ligament1
B = retina1
(b) to control the amount of light entering the eyeorto control the amount of light incident on the retina
allow change the size of the pupil1
14
Page 46 of 53
(c) (i) short sight
or
myopia
accept near sight1
(ii)
any 2 correct construction lines:
construction lines may be dotted or solid
construction lines must pass correctly through the lens
treat more than 2 construction lines as a list for marking2
upright image drawn at correct location
image must be to the left of the lens
upright orientation of image must be clear
the image line can be dotted or solidignore any arrows on construction rays
1
(d) to focus light from objects at different distances
accept can see objects (clearly) at different distances.
to focus light on the retina is insufficient1
Page 47 of 53
(e) (i) 0.5 metre(s) / m
the unit is not an independent mark
an answer 0.5 without a unit or with an incorrect unit scores 1 markora substitution 2 = 1 / f with the unit metre(s) / m scores 1 mark
2
(ii) 10 to 30 decreases linearly or at a constant rate
accept from 10 to 30 the decrease is 2.6 / 2.7(D)1
50 to 70 falls less rapidly after 60 years
accept it decreases at a decreasing rateaccept from 50 to 70 the decrease is 3.3 / 3.4(D)
1
10 to 30 decrease is less than 50 to 701
(iii) 0.8 (D)
accept answers in the range of 0.6 to 1.0 (D) inclusive1
[14]
(a) because the angle of incidence is greater than critical angle
accept the light is totally internally reflected1
15
(b) 41.8
allow 1 mark for correct substitution, eg 1.5 =
or
sin c =
or
c = sin-1
2
(c) (for both fibres) increasing the wavelength of light decreases and then increases thepercentage / amount of light transmitted
accept for 1 mark:
(for both fibres) increasing the wavelength (of light) to 5 (x 10-7
metres), decreases the (percentage) transmission1
(for both fibres) the minimum transmission happens at 5 (x 10-7 metres)or
maximum transmission occurs at 6.5 (x 10-7 metres)
accept for a further 1 mark:
(for both fibres) increasing the wavelength of the light from 5 (x 10-7
metres) increases the amount of light transmitted
increasing wavelength (of light), decreases the percentagetransmitted is insufficient on its own
1
Page 48 of 53
the shorter fibre transmits a greater percentage of light (at the same wavelength)
accept for 1 mark:Any statement that correctly processes data to compare the fibres
1
[6]
(a) (i) two correct rays drawn
1 mark for each correct ray
• ray parallel to axis from top of object and refracted through focus and traced back beyond object
• ray through centre of lens and traced back beyond object
• ray joining top of object to focus on left of lens taken to the lens refracted parallel to axis and traced back parallel to axis beyond object
2
16
an arrow showing the position and correct orientation of the image for their rays
to gain this mark, the arrow must go from the intersection of thetraced-back rays to the axis and the image must be on the sameside of the lens as the object and above the axis
1
(ii) (x) 3.0
accept 3.0 to 3.5 inclusiveor
correctly calculated
allow 1 mark for correct substitution into equation using their figures
ignore any units2
Page 49 of 53
(b) any two from:
in a camera the image is:
• real not virtual
• inverted and not upright
accept upside down for inverted
• diminished and not magnified
accept smaller and biggeraccept converse answers but it must be clear the direction of thecomparison
both parts of each marking point are required2
[7]
(a) 1.59
accept an answer that rounds to this
allow 1 mark for correct substitution into correct equation
2
17
ie refractive index =
(b) 2 lines correctly drawn from the top of the pin through the lens
allow 1 mark for each2
position of image correct
image must be upright1
[5]
(a) refracted into the block, angle r < i118
refracted correctly out of block, two rays in air parallel
judge by eye
if first mark not scored allow 1 mark for correct refraction shown asray leaves the block
1
(b) (i) the angle of refraction is (always) less than the angle of incidence1
the angle of refraction increases as the angle of incidence increases
accept angle i and angle r are not directly proportional
accept there is positive correlation1
(ii) (for the same angle of incidence) the angle of refraction in plastic is less thanthe angle of refraction in water
accept (for the same angle of incidence) plastic refracts light morethan wateraccept it is less
1
Page 50 of 53
(c) (i) accept any sensible suggestion to do with being able to see inside (duringdaylight hours)eg able to (see to) work / cook inside
accept to see what they are doing lights up the room is insufficientignore no need to pay for electricity
1
(ii) accept any ethical suggestion, eg
• fair access to energy for all
• unequal use of energy resources
• consequences for the future of decisions made now
• damage to global environment affects all
damage to the environment is insufficient1
[7]
(a) (i) headlight glass and castor oilorbakeware glass and olive oil
1
19
(ii) 1.60–1.33
either order1
(iii) lead (glass)
do not accept 1.621
(b) (i) normal1
(ii) i correctly labelled
allow I for i
accept with or without arc1
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(iii) r correctly labelled
allow R for r
accept with or without arc1
(c) (i) 1.48(375…)
1.5 scores 3 marks
allow:n = 0.719 / 0.484 for 2 marks
n = sin 46 / sin 29° for 1 mark3
(ii) car headlight glass
ecf from (c)(i)1
[10]
(a) refraction120
(b) towards the normal1
(c) (i) convex1
(ii) principal focus
accept focal point1
(d) parallel on left1
refracted towards the normal at first surface1
refraction away from normal at second surface1
passes through or heads towards principal focus1
(e) refractive index
accept material from which it is made1
Page 52 of 53
(radius of) curvature (of the sides)
accept shape / radius
do not accept power of lens
ignore thickness / length1
(f) 5 (dioptre)
1 / 0.2 gains 1 mark
0.05 gains 1 mark2
[12]
Page 53 of 53
