GCSEPhysics: Combined ScienceEdexcelExam Questions9. Electricity & Circuits9.1 Current, Potential Difference & Resistance

Current, Potential Difference & Resistance (Edexcel GCSE Physics: Combined Science)

Exam Questions

2 hours10 questions
Easy
Medium
Hard
1a3 marks

Figure 1 gives the names of three atomic particles and some descriptions of the charge on the particles and their position in the atom.


Draw one straight line from each atomic particle to its correct description.

fig-1-paper2f-june2019-edexcel-gcse-physics

Figure 1

How did you do?

1b1 mark
Figure 2 shows the junction of three wires, F, G and H, in a circuit.
The current in wire F is 6.0 A.
The current in wire G is 3.5 A.

Calculate the current in wire H.
fig-2-paper2f-june2019-edexcel-gcse-physics
Figure 2

current in wire H = ..................................... A

How did you do?

1c3 marks

A wire in a circuit carries a current of 0.9 A.
Calculate the quantity of charge that flows through the wire in 50 s.

State the unit of charge with your answer.

Use the equation

charge = current × time

quantity of charge = .................... unit .................

How did you do?

Did this page help you?

2a4 marks

Figure 1 shows an electrical circuit.

fig-1-paper2f-oct2021-edexcel-gcse-physics

Figure 1

Draw a circuit diagram of the electrical circuit in Figure 1 in the space below.

How did you do?

2b2 marks

When the current in a lamp is 0.15 A, the resistance of the lamp is 40 Ω.

Calculate the voltage across the lamp.

Use the equation

V = I × R

voltage = .............................................................. V

How did you do?

2c1 mark
Figure 2 shows an ammeter that can read up to 5 A.
fig-2-paper2f-oct2021-edexcel-gcse-physics

Figure 2

State the value of the current shown on the ammeter in Figure 2.


current = .............................................................. A

How did you do?

Did this page help you?

3a2 marks
Figure 4 shows the inside of a mains plug.
fig-4-paper2f-june2020-edexcel-gcse-physics

Figure 4

The mains plug has three safety features.

One of these safety features has been ticked in the table.

Put two more ticks in the table to show the other two safety features.

part of plug safety feature
cable grip ✓
earth wire  
fuse  
live wire  
neutral wire  

How did you do?

3b
Sme Calculator3 marks
Figure 5 shows a charger for a car battery.

fig-5-paper2f-june2020-edexcel-gcse-physics

Figure 5

i)
The meter on the battery charger shows the current supplied to a battery.
The meter on the battery charger is

[1]

  ☐ A an ammeter
  ☐ B an ohmmeter
  ☐ C a voltmeter
  ☐ D a wattmeter

ii)
The battery charger supplies a steady current of 2.5 A to the battery.
Calculate the charge flowing to the battery in 8 minutes.

Use the equation

charge = current × time

[2]

charge = .............................................................. C

How did you do?

3c
Sme Calculator2 marks
The transformer in another battery charger has a primary coil and a secondary coil.

The voltage across the primary coil = 230 V.
The voltage across the secondary coil = 15 V.
The current in the secondary coil is 3.1 A.

Calculate the current in the primary coil.

Use the equation

primary space current space equals space fraction numerator secondary space voltage space cross times space secondary space current over denominator space primary space voltage end fraction space



current = .............................................................. A

How did you do?

Did this page help you?

1a6 marks

A resistor is connected to a power supply.

The potential difference across the resistor is 6.0 V.

i)
Which of these corresponds to a potential difference of 6.0 V?
[1]

  ☐ A 6.0 joules per ohm
  ☐ B 6.0 amps per coulomb
  ☐ C 6.0 joules per coulomb
  ☐ D 6.0 amps per ohm


ii)
The resistor remains connected for a period of time.

The current in the resistor is 200 mA.

A total charge of 42 C flows through the resistor.

Calculate, in minutes, the time taken for this amount of charge to flow through the resistor.
[3]

time = ............................................... minutes

iii)
Calculate the total energy transferred by the 6.0V power supply when a charge of 42 C flows through the resistor.
[2]

energy = ............................................... J

How did you do?

1b2 marks

The resistor becomes warm while there is a current in it.

Explain why the resistor becomes warm.

How did you do?

1c3 marks

Figure 16 shows a cardboard tube with a wire coming out from each end.


fig-16-paper2h-june2018-edexcel-gcse-physics

Figure 16

There are two 10 ohm resistors inside the cardboard tube.

A potential difference of 6.0 V is connected between P and Q.

There is a current of 1.2 A in the wires.

Deduce how the resistors have been arranged inside the cardboard tube.

How did you do?

Did this page help you?

2a1 mark

Which of these symbols is used to represent a thermistor in an electrical circuit?

q9a-paper2f-june2019-edexcel-gcse-physics

How did you do?

2b8 marks
A student investigates how the current in a lamp changes with the potential difference across the lamp.

The student uses the results to calculate the resistance of the lamp.

The results are shown in the table in Figure 17.

potential difference in V current in A resistance in Ω
1.0 0.09 11
2.0 0.14 14
3.0 0.18 17
4.0 0.22 18
5.0 0.26  
6.0 0.30 20

i)
One value of resistance is missing from the table in Figure 17.
                        
Calculate the value of resistance that is missing from the table.

[3]

ii)
The student writes this conclusion:

‘The resistance of the lamp is directly proportional to the potential difference.’

Comment on the student’s conclusion. Use information from Figure 17 in your answer.

[3]

iii)
The student used a power supply that had fixed output voltage settings.
                           
Each of these outputs was a whole number of volts.
                               
Describe how the student could add a component to the circuit that would provide a continuously variable voltage across the lamp.

[2]

How did you do?

2c
Sme Calculator6 marks
Figure 18 shows a battery connected to a filament lamp.
fig-18-paper2f-june2019-edexcel-gcse-physics
Figure 18

Explain, in terms of the movement of charged particles, how energy is transferred from the battery, through the lamp, to the surroundings.

How did you do?

Did this page help you?

3a1 mark

Figure 17 shows two different types of the same circuit component.

fig-17-paper2f-oct2021-edexcel-gcse-physics

Figure 17


What is the name of this circuit component?

  ☐ A diode
  ☐ B light dependent resistor
  ☐ C thermistor
  ☐ D variable resistor

How did you do?

3b1 mark

Which row in the table describes the way that ammeters and voltmeters should be connected with a component in a circuit?

          ammeter voltmeter
      ☐ A in parallel in parallel
      ☐ B in parallel in series
      ☐ C in series in parallel
      ☐ D in series in series

How did you do?

3c9 marks

Figure 18 shows the results from an experiment where the potential difference (voltage) across a filament lamp was varied.


The current and voltage were measured.


fig-18-paper2f-oct2021-edexcel-gcse-physics

Figure 18

i)
Describe the relationship between the current and the voltage as shown in the graph in Figure 18.

[2]

ii)
Use the values of the voltage and current at point P and at point Q on the graph in Figure 18 to complete the table in Figure 19.

[2]

  Voltage in V current in mA
point P    
point Q    

Figure 19

iii)
Calculate the resistance of the filament lamp when the voltage is 4.5 V and the current is 51 mA.

Use the equation

R space equals space V over I

[2]

resistance = .............................................................. Ω

iv)
Explain why the resistance of the filament lamp changes as the voltage across it increases.

[3]

How did you do?

Did this page help you?

4a1 mark

Which of the following is not true about current?

 

square   A   Current has the same value anywhere in a closed loop

square   B   Current adds at the junctions

square   C   Current has the same value across components placed in parallel

square   D   Current is measured by an ammeter placed in series

How did you do?

4b2 marks

Figure 1 shows a circuit constructed by a student.

2-2-h-4a-current-ammeter-circuit

Figure 1

Determine the readings on ammeters A2 and A3.

   

   

A2 = .................................... A
 
 
A3 = .................................... A

How did you do?

4c2 marks

Figure 2 shows another circuit the student built.

2-2-h-4b-circuit-ammeter-voltmeter

Figure 2

Determine the reading on the ammeter and voltmeter.

   

   

ammeter = .................................... A
 
 
voltmeter = .................................... V

How did you do?

4d3 marks

Figure 3 shows another circuit constructed by the student.

Figure 3

2-2-h-4c-circuit-problem

Determine the resistance of resistor Z.

   

   

resistance = .................................... Ω

How did you do?

Did this page help you?

1a2 marks

A student investigates resistors connected in series in an electrical circuit.
The student has

  • a 3.0V battery
  • a 22 Ω resistor
  • a resistor marked X.

The student does not know the value of the resistor marked X.
The student decides to measure the potential difference (voltage) across resistor X.
Figure 15 shows the circuit that the student connected.

fig-15-paper2f-june2020-edexcel-gcse-physics

Figure 15

The circuit is connected incorrectly.
Describe how the student should correct the mistake.

How did you do?

1b9 marks

The student corrects the mistake.
The voltage across resistor X is 2.1 V.
The circuit is connected to a 3 V battery.

(i)
State the value of the voltage across the 22 Ω resistor.

[1]

voltage across 22 Ω resistor = .............................................................. V

ii)
The current in resistor X is 0.041 A.
The voltage across resistor X is 2.1 V.
Show that the resistance of resistor X must be about 50 ohms.
Use the equation

V = I × R

[2]

iii)
Calculate the power in resistor X when the voltage across X is 2.1 V and the current in resistor X is 0.041 A.

[2]

power = .............................................................. W

iv)
Calculate the overall resistance of the 22 ohm resistor and resistor X.

[2]

overall resistance = .............................................................. Ω

v)
The current in the circuit is 0.041 A.
The voltage across the battery is 3.0 V.
Calculate the energy transferred in 2 minutes.
Use the equation

E = I × V × t

[2]

energy = .............................................................. J

How did you do?

Did this page help you?

2a5 marks
Figure 19 shows two electrical devices for heating water.

fig-19-paper2h-june2019-edexcel-gcse-physicsFigure 19

i)
The current in the element of the immersion heater is 14 A.

The power of the immersion heater is 130 W.

Calculate the resistance of the immersion heater.

Give your answer to two significant figures.
[3]

resistance of immersion heater = ............................................... Ω

ii)
The current in the heating element of the kettle is 8.3 A.

State two differences between the movement of charge in the heating element of the kettle and the movement of charge in the immersion heater.
[2]

How did you do?

2b6 marks
Figure 20 shows the three-pin plug used to connect the kettle to the mains.

fig-20-paper2h-june2019-edexcel-gcse-physics

Figure 20

A fault occurs in the kettle causing the live wire to touch the metal case of the kettle.

Explain how the safety features of the plug operate when this fault occurs.

How did you do?

Did this page help you?

3a
Sme Calculator4 marks

A light-emitting diode (LED) is a diode that emits light when there is a current in it. 

Draw a circuit diagram showing an LED, connected so that it is lit, in series with a battery and a fixed resistor.

How did you do?

3b
Sme Calculator6 marks

The voltage across the LED when lit is 3.1 V and the current in the LED is 0.030 A.

i)
Add to the diagram in (a) to show how these readings were obtained.
[2]
ii)
Calculate the value of the resistance of the LED when lit.
[2]
iii)
Explain the effect of adding connected an identical LED in series with the first LED.
[2]

How did you do?

3c
Sme Calculator5 marks

The diagram shows a power supply with a voltage of 12 V connected in series with a lamp and a heater.

2-1-q5c-h-lamp-heater-circuit-sq-igcse

The voltage across the lamp is 3.2 V and the current in the lamp is 1.5 A.

i)
Calculate the resistance of the heater.
[3]
ii)
Calculate the power of the heater.
[2]

How did you do?

Did this page help you?