Elecricity Multiple Choice Questions Set 2

Which component does this circuit symbol represent?

• diode

• lamp

• LED

• motor

What is the equation that links charge flow, current and time?

• charge flow = current × time

• charge flow = current / time

• current = charge flow × time

• current = time / charge flow

What is the unit for resistance?

• amp (A)

• coulomb (C)

• ohm (Ω)

• volt (V)

An appliance has a power rating of 1200W. Calculate the energy transferred by the appliance in 20 seconds.

• 60J

• 240J

• 600J

• 24 000J

Which statement applies to a light-dependent resistor (LDR)?

• the resistance of an LDR decreases as light intensity decreases

• the resistance of an LDR decreases as light intensity increases

• the resistance of an LDR increases as temperature decreases

• the resistance of an LDR increases as temperature increases

Which statement refers to parallel circuits?

• the current through each component is the same

• the potential difference across each component is the same

• the total potential difference of the power supply is shared between components

• the total resistance of the circuit is the sum of the resistance of each component

Which colour is used to colour code the live wire in an electrical cable?

• blue

• brown

• green and yellow stripes

• red

What is the equation that links current, power and resistance?

• current = (power)² × resistance

• current = resistance / power

• power = (current)² × resistance

• power = resistance / current

An electric heater has a power of 2300W. How much current passes through the heater when it is plugged into the UK mains electricity supply (230V)?

• 10A

• 23A

• 46A

• 115A

What is the role of step-up transformers in the National Grid?

• they decrease the potential difference from the power station to the transmission cables

• they decrease the potential difference from the transmission cables for domestic use

• they increase the potential difference from the power station to the transmission cables

• they increase the potential difference from the transmission cables for domestic use