Electrical System

What is the purpose of having a battery in the electrical circuit?

• It powers the electricity.

• It is an energy source.

• It contains chemicals.

• It has both the positive and negative terminals

Study the circuit diagram below.

Which one of the following will make each bulb in the circuit less bright?

• Removing one bulb from the circuit

• Removing the switch from the circuit

• Adding one bulb in series to the circuit

• Adding one battery in series to the circuit

Four pupils list down ways of using electricity responsibly in their daily lives as shown below.

Alicia: I use energy-saving bulbs for all the lights at home.

Billy : I always leave the laptop charging when I am not using it.

Citra: I switch on the fan and air-conditioner together to cool the room.

Dini: I always switch off all the fans and lights when I am the last to leave the classroom.

Which of the pupils are helping to conserve electricity?

• Alicia

• Billy and Citra

• Alicia and Dini

• Billy, Citra and Dini

Irfan wants to find out if the arrangement of the bulbs in a circuit affects their brightness. He sets up four circuits as shown below.

Which pair of circuits should he use to ensure a fair test?

• P and S

• P and Q

• R and P

• R and Q

Study the circuit diagram below.

What can object X be so that only bulbs L and M light up?

• Battery

• Copper wire

• Rubber band

• Aluminum foil

Halimah wants to find out how the arrangement of the batteries in a circuit will affect the brightness of the bulbs. Which variables should be kept constant?

A: Number of bulbs in each circuit.

B: Brightness of bulbs in each circuit.

C: Number of batteries in each circuit.

D: Arrangement of batteries in each circuit.

• A only

• C only

• A and C only

• A, B, C and D

Damien set up an electric circuit as shown below. A piece of butter is placed on material Z. The butter started to melt when he turned on the switch.

What can material Z be?

• glass

• wood

• plastic

• copper

Xue Li placed 4 bars, each of different material, A, B, C and D, in an electric circuit below. Two bars are conductors of electricity while the remaining two bars are non-conductors of electricity.

Where should Xue Li place the two bars of non-conductors of electricity so that only two bulbs will light up in the circuit?

• A and D

• A and C

• B and D

• B and C

Minghui set up a circuit as shown.

All five bulbs were lit when all four switches were closed.

He wanted four bulbs to be lit by opening only one switch.

Which switch should he open?

• A

• B

• C

• D

Joseph set up the circuit diagram as shown below.

He realised one of the bulbs had blown and all the other bulbs did not light up. Which bulb had blown?

• A

• B

• C

• D