µ GCSE | Resistors

10 quick questions - for GCSE or iGCSE


10 minutes maximum! (can you do it in 5?)

1. Resistance is measured in 'Ω'. This is the symbol for the unit

  • A. watts
  • B. ohms
  • C. resists
  • D. coulombs


2. The formula to calculate resistance (often called Ohm's Law) is

  • A. resistance = voltage x current2   (R=V.I2)

  • B. resistance = voltage ÷ current    (R= V/I)

  • C. resistance = current ÷ voltage    (R= I/V)

  • D. resistance = voltage x current     (R=V.I)

3. 0.3 kΩ is the same as

  • A. 3Ω
  • B. 30Ω
  • C. 300Ω
  • D. 3000Ω

4. What is the resistance of this resistor?

  • A. 0.2Ω
  • B. 2Ω
  • C. 5Ω
  • D. 80Ω


5. What current flows in this circuit?

  • A. 0.2A
  • B. 2A
  • C. 5A
  • D. 150A



6. What is '2mA' in amps?

  • A. 2000A
  • B. 200A
  • C. 0.02A
  • D. 0.002A



7. What is the voltage of this power supply?

  • A. 1.5 mV
  • B. 6V
  • C. 15V
  • D. 6000V



8. A steel wire has a resistance. Which of these correctly describes the change to the resistance if the wire is made longer, or thicker? (with a bigger radius).


Longer wire Thicker wire
higher resistance lower resistance
lower resistance higher resistance
lower resistance lower resistance
higher resistance higher resistance


Q9 & 10.

In this circuit, a single resistor R is connected to a cell. The total current is given by the ammeter shown.



9. If I change the circuit and put 2 of these resistors in series, what happens?

  • A. The current increases as the total resistance increases.
  • B. The current increases as the total resistance decreases.
  • C. The current decreases as the total resistance increases.
  • D. The current decreases as the total resistance decreases.





10. How does the total current change , compared to a single resistor, if I put 2 of the resistors in parallel?

The total current is .