Electrical Systems

In a circuit diagram, this symbol represents a

• switch

• ammeter

• cell

• light bulb

Which light bulb(s) would not light up?

• A

• B, C, D

• A, B, C, D

• None

What is used to measure electric current?

• Voltmeter

• Ammeter

• pH meter

What type of circuit is this?

• Series

• Parallel

• Simple

In a series circuit, how is the brightness of a light bulb affected when another bulb is connected?

• It gets brighter

• It stays the same

• It gets dimmer

• It goes out

Why are household appliances connected in parallel?

• It is cheaper.

• It uses less electricity

• If an appliance is faulty, the other appliances will keep working.

An appliance requires 27 A of current to function properly. What should the rating of the fuse to be fitted in the appliance?

• 25 A

• 27 A

• 30 A

• 50 A

The power ratings and duration of daily usage of an oven and air-conditioner is shown. Calculate the total amount of electrical energy used in kWh by the oven and the air-conditioner daily.

• 300

• 755

• 45000

• 45300

This is an electrical hazard which can lead to a fire. Which statement best explains why overloading may cause a fire?

• The current flowing is too large.

• The fuse will blow.

• There will be a short circuit.

• The total voltage will increase.

An electric hot plate uses 2000 J of energy in 5 s. What is the power?

• 5

• 400

• 2000

• 10000