Domestic Electricity

What unit of power is normally used for domestic electricity?

• Kilowatt

• Joule

• Newton

• Ampere

What are units of energy measured in?

• Joules

• Watts

• Kilowatt-hours

• Newtons

Is mains electricity an a.c supply or a d.c supply?

• a.c supply

• d.c supply

Define direct current.

• A type of electrical current in which the flow of electrons is in one direction only.

• A type of electrical current in which the flow of electrons reverses direction periodically.

• A type of electrical current that varies in magnitude and direction.

• A type of electrical current that flows in multiple directions.

Define alternating current.

• A type of electrical current in which the direction of the flow of electrons switches back and forth at regular intervals or cycles.

• A type of electrical current that flows in one direction only.

• A type of electrical current used primarily in batteries.

• A type of electrical current that increases in amplitude over time.

What is the frequency and voltage of the UK mains electricity supply?

• 230 V, 50 Hz

• 120 V, 60 Hz

• 240 V, 60 Hz

• 220 V, 50 Hz

How many wires are usually in the cables connecting electrical appliances to the mains? Name these wires.

• Two wires: Live and Neutral

• Three wires: Live, Neutral, and Earth

• Four wires: Live, Neutral, Ground, and Control

• One wire: Live only

State the insulation colour used on the Earth wire.

• Green and yellow

• Red

• Blue

State the insulation colour used on the live wire.

What does an MCB stand for?

• Miniature Circuit Breaker
• Mega Circuit Breaker
• Micro Circuit Breaker
• Maximum Circuit Breaker