Electricity Multiple Choice Questions Set 3

Which component does this circuit symbol represent?

• diode

• LED

• LDR

• variable resistor

What is the equation that links current, potential difference and power?

• potential difference = current / power

• potential difference = power × current

• power = potential difference / current

• power = potential difference × current

What is the unit for power?

• coulomb (C)

• ohm (Ω)

• volt (V)

• watt (W)

A current of 5A passes through a variable resistor with a resistance of 12Ω. What is the potential difference across the resistor?

• 2.4V

• 60V

• 240V

• 300V

Which statement does not apply to a diode?

• it is used to convert an alternating current into a direct current

• it allows current to flow in one direction only

• it can be used to vary the resistance of a circuit

• it has very high resistance in the reverse direction

What is the potential difference of the UK mains electricity supply?

• 12V

• 50V

• 230V

• 450V

Three lamps are connected in series with a battery. Lamp 1 has a resistance of 10Ω, lamp 2 has a resistance of 8Ω and lamp 3 has a resistance of 12Ω. What is the total resistance of the circuit?

• 30Ω

• 12Ω

• 8Ω

• 6Ω

What is the equation that links charge flow, energy transferred and potential difference?

• charge flow = energy transferred × potential difference

• charge flow = (energy transferred / potential difference)

• energy transferred = charge flow × potential difference

• energy transferred = (potential difference / charge flow)

30C of charge passes a point in a circuit in 2 minutes. What is the current through the circuit?

• 0.25A

• 25A

• 60A

• 1300A

What is alternating current?

• current that is always in the same direction

• current that repeatedly changes direction

• current that can be varied using a variable resistor

• current that is used up by a component