Electricity at home

Mains electricity is...

• an alternating current (a.c.) supply

• a direct current (d.c.) supply

• a variable current (v.c) supply

• a continuous current (c.c) supply

the pins of a 13 A plug are usually made from...

• gold

• aluminium

• brass

• copper

What is the potential difference of mains electricity?

• 320 V

• 230 V

• 100 V

• 430 V

What is the frequency of mains electricity?

• 50 KHz

• 250Hz

• 50 Hz

• 150 Hz

two core cables don't need which wire?

• live wire

• hot wire

• earth wire

• neutral wire

what is the purpose of the live wire?

• completes the circuit

• melts if too much current flows

• only carries current when there is a fault

• provides the potential difference

what colour is the casing of the neutral wire?

• red

• blue

• brown

• green and yellow

power is defined as...

• the strength of the current

• the rate of energy transfer

• energy transferred per Coulomb of charge

• the ratio of potential difference across a component to the current through it.

the unit of power is the...

• Watt

• Joule

• Ohm

• Newton

the equation that links power (P), current (I) and potential difference (V) is...

• P=I/V

• V=IP

• I=VP

• P=IV