Edexcel GCSE Additional Science Topic P2.2 Controlling and Using Electricity Test 12_13

TEST 1 – PART A

YEAR 5 TRIPLE SCIENCE PHYSICS 1 Turn over

Surname

Name

American Academy Larnaca

Year 5 Physics

Semester 1

Test 1

Unit P2

Physics for your future

Topic 1 Static and current electricity Topic 2 Controlling and using electric currents Monday 21 October 2012 Part A

Time: 20 minutes

• The total marks for this part is 20. • The total marks for the paper is 40. • The marks for each question are shown in square brackets.

Use this as a guide as to how much time to spend on each question. • Questions labelled with an asterisk (*) are ones where the quality of your written communication

will be assessed. You should take particular care with your spelling and grammar, as well as the clarity of expression, on these questions.

• Answer the questions in the spaces provided. There may be more space than you need.

TEST 1 – PART A


FORMULAE

You may find theses formulae useful

charge = current × time Q = I × t

potential difference = current × resistance V = I × R

electrical power = current × potential difference P = I × V

energy transferred = current × potential difference × time E = I × V × t

force = mass × acceleration F = m × a

weight = mass × gravitational field strength W = m × g

momentum = mass × velocity p = m × v

work done = force × distance moved in the direction of the force E = F × d

GPE = m × g × h

Do not forget to include units in all your answers.

TEST 1 – PART A


_______________________________________________________________________________________ 1. (a) Join each of the particles on the left to the correct description on the right.

[3 marks]

• a positive particle in the nucleus

electron •

• a particle in the nucleus without charge

neutron •

• a light negative particle

proton •

• a negative particle in the nucleus

(b) A piece of acetate rod is rubbed with a cloth.

The rod receives +0.0000002 C of charge.

(i) Put a cross ( ) in the box next to the correct answer.

[1 mark] The cloth then

A −0.0000002 C of charge

B receives +0.0000002 C of charge

C receives −0.0000001 C of charge

D remains neutral

(ii) Put a cross ( ) in the box next to the correct answer.

[1 mark] The rod turned positive because

A it gained electrons

B it gained protons

C it lost electrons

D it lost protons

[Total for Question 1 = 5 marks]

_______________________________________________________________________________________

acetate rod

cloth

TEST 1 – PART A


_______________________________________________________________________________________ 2. Laser printers use static electricity to spread the toner onto the paper.

Below you can see some details how the laser printer works.

The toner particles become negatively charged. The drum becomes negatively charged where there are no letters and remains neutral where there should be printing.

(a) The toner particles are attracted to the neutral parts of the drum by induction.

Describe what this means. [2 marks]

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

Toner negatively charged transferred onto drum

Drum negatively charged where there is no printing neutral where there is printing

Paper collects toner from drum

Laser beam makes parts with printing neutral

TEST 1 – PART A


(b) Explain why the toner particles are repelled by the parts of the drum that should not

have any printing. [2 marks]

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (c) The paper gets charged as well to attract the toner particles.

State the charge that the paper receives. [1 mark]

………………………………………………………………………………………………………………………………………………………………………

[Total for Question 2 = 5 marks] _______________________________________________________________________________________

TEST 1 – PART A


_______________________________________________________________________________________ 3. This question investigates some of the dangers of static electricity. (a) Below you can see pictures shot by a CCTV camera at a refuelling station.

It shows how static electricity can cause a fire.

(i) Explain how charge can accumulate on the driver.

[2 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (ii) Explain how static electricity can cause such a fire.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (iii) Some people have suggested placing signs like the ones below around the fuel station.

Explain how this could help prevent fires.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

TEST 1 – PART A

YEAR 5 TRIPLE SCIENCE PHYSICS 7

(b) Lightning is a phenomenon based on static electricity.

(i) During a lighting flash 15 C of charge reach the Earth in 0.0005 sec.

Calculate the average current delivered by the lightning. [2 marks]

Current ………………………… * (ii) Currents up to 1A can cause severe burns or death to humans.

Describe how lightning occurs. Use your answer in (i) to explain why lightning is dangerous. Describe how this problem is tackled in modern buildings today.

[4 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


TOTAL FOR PART A = 20 MARKS _______________________________________________________________________________________

END TOTAL FOR PAPER = 40 MARKS

TEST 1 – PART B


Surname

Name

American Academy Larnaca

Year 5 Physics

Semester 1

Test 1

Unit P2

Physics for your future

Topic 1 Static and current electricity Topic 2 Controlling and using electric currents Monday 21 October 2012 Part B

Time: 20 minutes

• The total marks for this part is 20. • The total marks for the paper is 40. • The marks for each question are shown in square brackets.

Use this as a guide as to how much time to spend on each question. • Questions labeled with an asterisk (*) are ones where the quality of your written communication

will be assessed. You should take particular care with your spelling and grammar, as well as the clarity of expression, on these questions.

• Answer the questions in the spaces provided. There may be more space than you need.

TEST 1 – PART B


FORMULAE

You may find theses formulae useful

charge = current × time Q = I × t

potential difference = current × resistance V = I × R

electrical power = current × potential difference P = I × V

energy transferred = current × potential difference × time E = I × V × t

force = mass × acceleration F = m × a

weight = mass × gravitational field strength W = m × g

momentum = mass × velocity p = m × v

work done = force × distance moved in the direction of the force E = F × d

GPE = m × g × h

Do not forget to include units in all your answers.

TEST 1 – PART B


_______________________________________________________________________________________ 1. (a) Join each quantity on the left to its description on the right.

[2 marks]

Current in Amperes • • Number of Joules per second

Potential difference in Volts • • Number of Joules per Coulomb

Power in Watts • • Number of Coulombs per second

(b) A cell provides 8000 C of charge at 1.5 V.

(i) Calculate the total energy stored in the cell.

[2 marks]

………………………… (ii) Put a cross ( ) in the box next to the correct answer.

[1 mark] What type of current does the cell provide?

A AC only

B DC only

C Both AC and DC

D None of the above

[Total for Question 1 = 5 marks]

_______________________________________________________________________________________

TEST 1 – PART B


_______________________________________________________________________________________ 2. A toaster and a microwave oven are connected in parallel on the same socket.

(a) (i) The mains provide a potential difference of 230 V.

The microwave oven has a power input of 1.1 kW. Show that the current in the microwave oven is 4.8 A.

[1 mark] The current coming out of the mains socket is 10.9 A (ii) Put a cross ( ) in the box next to the correct answer.

[1 mark] To measure the current provided by the mains we should connect

A an ammeter in parallel with the toaster

B an ammeter in series with the mains

C a voltmeter in parallel with the mains

D a voltmeter in series with the toaster

(iii) Calculate the current in the toaster.

[1 mark]

C …………………………

mains 230 V

microwave oven

toaster

I = 10.9 A

TEST 1 – PART B


(b) (i) Calculate the resistance of the microwave oven when it operates normally.

[2 marks]

R ………………………… (ii) Both devices use the same voltage from the mains.

Use your answers in (a) to deduce which device has the greatest resistance. Give a reason why you think so.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… (c) The microwave oven uses a component with the following characteristic.

Name the component and describe its function in the microwave oven.

[1 mark] ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


Voltage

Current

TEST 1 – PART B


_______________________________________________________________________________________ 3. Modern buildings in hot countries have blinds to control the amount of light and heat radiation

getting into the building in order to avoid overheating. Many of these systems can be controlled automatically using an LDR and a thermistor.

(a) The electrical source provides a voltage of 110 V.

It gives out a current of 8 A during the closing or opening of the blinds. The energy used in order to completely close or open the blinds is 66 kJ. Calculate the time necessary to completely close or open the blinds. Be careful with units.

[2 marks]

T ………………………… (b) The graph below shows how the current in the circuit affects the extend

to which the blinds close.

Explain how the LDR controls the extent to which the blinds close.

[2 marks] ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………

0

20

40

60

80

100

Percentage (%) the blinds are closed

Current

Blinds control

mechanism

electrical source

TEST 1 – PART B


* (c) The graph below shows the way current changes with voltage in a filament lamp.

In the same space sketch the graph of how current changes with voltage in a thermistor. Explain the difference between the two graphs. Refer to the way electrons move through a conductor and the energy transfers.

[2 marks]

……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………………………………………


TOTAL FOR PART B = 20 MARKS _______________________________________________________________________________________

END TOTAL FOR PAPER = 40 MARKS

potential difference

current

TEST 1 – MARK SCHEME – PART A


MARK SCHEME

PART A

p. 3

1. (a) • a positive particle in the nucleus

electron •

• a particle in the nucleus without charge

neutron •

• a light negative particle

proton •

• a negative particle in the nucleus

Each correct match [1 mark] (b) (i) A [1 mark] (ii) C [1 mark] p. 4 & 5 2. (a) Any two from [2 marks]

Toner (particles) repel e−s / similarly charged particles Toner particles separate / divide +ve and –ve particles / charges (in drum) +ve charges gather on surface / attract –ve toner (particles)

(b) Both are negative / have the same charge [1 mark]

They repel / Like charges repel (or similar) [1 mark] (c) +ve / opposite to toner (particles) [1 mark]

TEST 1 – MARK SCHEME – PART A


p. 6 & 7 3. (a) (i) By friction [1 mark]

Transfer of charge / e−s (or similar) [1 mark] (ii) Any one from [1 mark]

Spark / Discharge ignites fuel Spark / Discharge as objects tend to become neutral / equally charged Spark / Discharge due to large attraction from unlike charges

(iii) By touching people get discharged / lose their charge / charge flows to Earth [1 mark] (b) (i) Q = I × t => 15 = I × 0.0005 formula &/V substitution [1/2 mark]

I = 15 / 0.0005 rearrangement [1/2 mark] I = 30 000 A calculation [1/2 mark] unit [1/2 mark]

* (ii) Lightning = Discharge due to large amounts of charge accumulated in clouds & Earth

Current in (i) >> currents dangerous for humans Lightning conductors / Earthing allows safe discharge Lightning conductors made of any material such as metal

Level Marks 1 1 – 2 Refers to at least two of the following

Compares currents Attempts to connect lightning with static electricity Refers to lightning conductors (perhaps not by name)

2 3 − 4 Describes lightning as discharge due to charge accumulation Refers to lightning conductors (perhaps not by name) Mentions material e.g. good conductor or metal

TEST 1 – MARK SCHEME – PART B


MARK SCHEME

PART B

p. 3

1. (a) Current in Amperes • • Number of Joules per second

Potential difference in Volts • • Number of Joules per Coulomb

Power in Watts • • Number of Coulombs per second

One correct matching [1 mark]; All matching correct [2 marks] (b) (i) E = Q × V OR Ratio: 1.5 V => 1 C 1.5 J 8000 C ? [1/2 mark] E = 8000 × 1.5 [1/2 mark]

E = 12 000 J calculation [1/2 mark] unit [1/2 mark] (ii) B [1 mark] p. 4 & 5 2. (a) (i) Any two from [1 mark]

1.1 kW = 1100 W conversion [1/2 mark] P = I × V => 1100 = I × 230 formula &/V substitution [1/2 mark] I = 1100 / 230 (= 4.78 A) rearrangement [1/2 mark]

(ii) B [1 mark] (iii) 10.9 – 4.8 = 6.1 (A) subtraction [1/2 mark] calculation [1/2 mark]

Ignore if unit absent or wrong (since given) (b) (i) V = I × R => 230 = 4.8 × R formula &/V substitution [1/2 mark]

R = 230 / 4.8 rearrangement [1/2 mark] R 47.9 Ω 48 Ω calculation [1/2 mark] unit [1/2 mark]

(ii) Microwave oven larger resistance [1/2 mark]

Smaller current [1/2 mark] OR reverse reasoning for toaster

(c) Diode [1/2 mark]

AND Any one from [1/2 mark] Allows current only in one direction (or similar) Rectifies current / Changes AC DC (or similar)

TEST 1 – MARK SCHEME – PART B


p. 6 & 7 3. (a) E = I × V × t => 66 000 = 8 × 110 × t formula &/V substitution & conversion [1/2 mark]

t = 66000 / (8 × 110) = 66000 / 880 (rearrangement) [1/2 mark] t = 75 sec calculation [1/2 mark] unit [1/2 mark]

(b) As light intensity increases => LDR resistance decreases [1 mark]

AND Any one from [1 mark] => Current in circuit increases => Blinds close more / to greater extent etc. OR reverse reasoning As light intensity decreases => LDR resistance increases [1 mark] AND Any one from [1 mark] => Current in circuit decreases => Blinds close less / to smaller extent / open more etc.

* (c)

For correct graph [1 mark] The remaining 3 marks allocated for the following Filament lamp: I / V increases => R increases Thermistor: I / V increases => R decreases e−s move through component colliding with atoms / lattice ions => pass on some of their KE => atoms / lattice ions vibrate more => temperature increases ( different effect on thermistor and filament lamp)

Level Marks 1 1 Describes difference in shape, no reference to R

May refer to e− movement and heat w/o elaboration 2 2 Refers to changes in R w/o specifying the change in each component

Refers to collisions and increase in temperature or heat 3 3 Refers to changes in R for each component clearly

Explains temp rise / heat as e−s passing KE or causing increased vibrations

potential difference

current

Edexcel GCSE Additional Science Topic P2.2 Controlling and Using Electricity Test 12_13

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