Hurst ScienceYear 7 Physics

HurstHURSTPIERPOINT COLLEGE

Energy and Electricity Test

Time Allowed: 45 minutes

TOTAL

°/0'0

Grade

CG

The answers should be written on the question paper.

Attempt all of the questions 1-8

Calculators and rulers may be used.

Name: Mft^»

Q1.(a) A torch battery is an energy resource. How is the energy stored in a torch

battery?Tick the correct box.

as chemical energy^

as kinetic energy

as potential energy

as thermal energy

1 mark

(b) When a torch is switched on, energy is transferred from the battery to thebulb.How is energy transferred from the battery to the bulb?Tick the correct box.

by electricity^

by light

by sound

by thermal energy

1 mark

(c) Energy is transferred from the torch bulb to the surroundings.

Choose from the following terms to complete the sentences.

electricity light sound thermal transfer

(i) Energy is transferred from the torch bulb to the surroundings in auseful way by ....Ls

Q2.(a) Draw a line from each circuit symbol below to the correct name.

Draw only four lines.

circuit symbol

^2>-

-IH

A

(b) Fred made circuit 1 as shown below.

circuit 1

name

ammeter

switch

motor

battery

bulb

A

Give the name of the part that is the energy source for the circuit.

M .4^m. ....fcr... .^a.^ )..t •

(c) Fred then made circuit 2 as shown below.

circuit 2

6

In the table below, tick a box to show whether circuit 1 and circuit 2 areseries or parallel circuits.Tick only two boxes.

series parallel

circuit 1 ^circuit 2 ^

(d) What metal is usually used for wires in electric circuits?

.C.cp.p.(x....(.^.cc£-f.':....ft^m!n^mC

Q3.Jenny put a springover a wooden rod.

She pressed thespring down 2 cm.

woodenrod

spring

c ^

She let go of the springand measured the

height it reached.

^

heightreached

-- 2cm

nottosca/e

Jenny repeated her experiment. She pressed the spring down more each time.Her results are shown in the graph below.

90

80-

70

60

height the spring 50reached (cm)

40

30

20

10

00

-44. )

f tH-

1 2 3 4 5

distance the springwas pressed down (cm)

(a) Use Jenny's graph to complete the table below.

distance the spring waspressed down (cm)

height the springreached (cm)

2 2.0

3 M-5

4 ^•0/(^\/5< ^cx^ cu^3 Ct

Q4.(a) Max built circuit 1 as shown below.

A

^

DB E

c

s

circuit 1

He closed the switch, S, and all the bulbs came on.One of the bulbs then broke and all the bulbs went off.

Which bulb must have broken?Give the letter.

e

(b) Max built circuit 2 as shown below.He connected a plastic comb and a metal key in different parts of thecircuit.

p

1 mark

Q

plastic comb

^-

Look carefully at circuit 2.

.^'

Q5.In a power station, coal can be used to generate electricity.

*?s.*

^^- :'.s

s

coal isburnt

water

changesto steam

steam

tojrns a

turbine

the turbinegenerateselectricity

(a) Use words from the box to answer the questions below.

chemical

kinetic

electrical gravitational potential

light sound thermal1 mark

(i) What is the useful energy transfer when coal is burnt?

..c^.e.^.l.c^.......... energy is transferred to ..h.\A.aWJL....(.

(b) Wind turbines are also used to generate electricity.The wind turns the turbine blades and the turbineblades turn a generator.

&

Complete the sentence to show the useful energy transfer in a wind turbineand generator.

....^-.\.r^L(..fcfc)... energy is transferred to eU^yn.i-cU .. . energy1 mark

(c) Suggest one disadvantage of using wind to generate electricity.

f^\

Q6.(a) The diagram shows the circuit used to investigate the resistance of a

sample of a material.The diagram is not complete; the ammeter and voltmeter are missing.

6V

m^r bf ^if,^fW

A

L/\

Material

<

-CS>^B-

mu^by p:.n\JOi;\ ^i-Y'.CX?£:rL.(:tl

(i) Draw the symbols for the ammeter and voltmeter on the diagram inthe correct places.

(ii) How can the current through the material be changed?

^.!^.

(I) The current through a 20 cm length of conducting putty was 0.15 A.

Use Graph 1 to find the resistance of a 20 cm length of conductingputty.

30Resistance = ..................................^..^........... ohms

(ii) Use your answer to (b) (i) and the equation in the box to calculate thevoltage across a 20 cm length of conducting putty.

(1)

voltage = current x resistance

Show clearly how you work out your answer.

\/ = 0*

(i) What is the relationship between the resistance and the thickness ofthe conducting putty?

..t)^...^:cML.^...^^H:,^..^.^.J^^.....^....^&^tm.^..

..^«.c.^h....

Q7.The drawing shows a hairdryer.

switch 2

switch 1

Ben drew the diagram below to show the circuit of the hairdryer.

switch 1•o ^~^»

motor

switch 2

mains powersupply

heater

(a) Complete the energy chain below for the hairdryer.

Electrical

-> +h)nn^cU

•> scavncl

c.a^ ^S^P'^^ ^\Vr}C\-

cXG^My'' C\(-t-^-^ y^CI^L, ,

1 mark

(b) Which of the switches must be closed for the heater to work? Tick thecorrect box.

switch1 only

switch2 only

switches1 and 2

neither switch1 nor 2

711 mark

(c) With this circuit, is it possible to have the heater on when the motor isswitched off?

NC

Explain your answer.

.b?.cc\;e

STRETCH QUESTION fA* Lovoll

O^ly atteropt-tbis. question-if you have finished and checked the rest-oftbajquestioi^papers.

Q8*.

(a) The Sankey diagram for a low energy light bulb, known as a CFL, is shown below.

Useful^^ctACcU.

Enftrgy input20 joules

j4.-i J- . J i

(iv) CFLs contain mercury. Mercury is a potsonous substance.

It is important that old CFLs are sent for recyding and not thrown into a rubbish bin.

Suggest one reason why.

OQ) cfli_c{. ^ ^ mf'**-r'"'»**-T-'T-H -f--t --t - -!—^ -' -t-t -

?44J--^-1^^^'TriTT:H-rt-:-t~4-r-r.i:^iiLrlJi-1-4-' i-

1 ; ^ *

!^' r—^.••t-r;-n-

?HT-—>.-

-:titH'I ( t t ) »

^*4.^ ^4'-+-4-*-[;:^tru:'.[•n:irtr:i

-f

.^s.

i

I

LEDbuto

-+-4^

3:

0 5 10 15Time in seconds

20

Apart from a higher efficiency, si^gest one advantage of using an LED bulb rather than aCFL

(d) At the moment, LED bulbs are much more expensive to buy than CR.S.

Which[twojof the following would a homeowner need to know to decide whether it wouldbe cost::eTfective to replace a CFL with an equally bright LED bulb?

Tick (v