PHYSICS FORM 4- MAINS ELECTRICITY

1.	What do electrical appliances transfer?

A. Gas

B. Electricity

C. Coal

D. Oil

2.	What does the power of an electrical appliance represent?

A. The amount of current that passes through the appliance

B. The rate at which it transforms energy

C. The speed at which it performs a task

D. The size of voltage that the appliance uses

3.	Most appliances have their power consumption and potential difference printed on them. Which of the following can be calculated from these values?

A. Internal resistance of transformer

B. Momentum

C. Current

D. Work done

4.	What size of fuse would be required for an electrical appliance which has a power rating of 700W and uses a mains voltage at 240V?

A. 1A

B. 2.5A

C. 3A

D. 5A

5.	What is the main difference between a circuit breaker and a fuse?

A. A circuit breaker can be used to control electrical circuits

B. A circuit breaker can be reset whilst a fuse needs to be replaced

C. A fuse can be reset whilst a circuit breaker needs to be replaced

D. A fuse can be used to control electrical circuits

6.	Some cables for electrical appliances only have two wires within them. Which wire is missing from this configuration?

A. Earth

B. Neutral

C. Live

D. The red one

7.	Why do some appliances not need an earth wire?

A. These appliances do not need an earth wire as they don’t use electricity

B. They are double insulated so that shocks cannot be caused if the appliance malfunctions

C. They have been incorrectly wired

D. All appliances need an earth wire, some do not have a neutral wire

8.	If an appliance uses mains electricity at 240V and the service manual for the appliance recommends using a fuse of 13A, what is the power consumption it can safely use?

A. 2020W

B. 2550W

C. 3120W

D. 3520W

9.	What kind of a plug is used to connect electrical appliances to a mains socket in the Kenya?

A. 2-pin plug

B. 3-pin plug

C. 4-pin plug

D. 5-pin plug

10.	Which colour wire is the live wire in a 3-pin plug?

A. Blue

B. Yellow and green

C. Brown

D. Red