Using Electricity in the Home Quiz
Studying this course? Keep your progress in one place.
Pick an answer for each. Quizzes never use energy.
5 questions, one answer each
Each answer is checked as you go, with why.
See all 5 questions
1. What is the key difference between ac and dc?
- A. AC has a higher voltage than dc
- B. AC repeatedly reverses direction; dc always flows the same way
- C. DC is only produced by power stations
- D. AC cannot flow through metal wires
2. What is the purpose of earthing in a household circuit?
- A. To increase the appliance's power output
- B. To provide a safe path for fault current if a metal casing becomes live
- C. To reduce the frequency of the ac supply
- D. To store extra electrical charge
3. How does a circuit breaker differ from a fuse?
- A. A circuit breaker is slower and must be replaced
- B. A circuit breaker trips faster and can be reset
- C. A fuse can be reset but a circuit breaker cannot
- D. There is no difference
4. A supply has a frequency of 50 Hz. What is its period?
- A. 50 s
- B. 0.5 s
- C. 0.02 s
- D. 2 s
5. An appliance has a plastic casing with no exposed metal parts and no earth wire in its cable. Why is this considered safe?
- A. Because plastic conducts fault current safely to the ground
- B. Because the appliance is double insulated, so there is no way for an exposed part to become live
- C. Because plastic appliances never develop electrical faults
- D. Because the fuse rating is always lower for plastic appliances