Electricity

The diagram shows a circuit with three identical bulbs, X, Y and Z.

Which of the following statements is correct?

• The switch controls bulbs X and Z.

• The bulbs can be controlled independently.

• When bulb Z fuses, bulb X and Y will not light up.

• All the bulbs are equally bright.

When the switch is closed, only two bulbs lit up. Which one of the four blocks is an insulator of electricity?

• A

• B

• C

• D

When two of the bulbs in the circuit fused, the other two bulbs remained lit. Which were the two bulbs that had fused?

• E and F

• E and H

• G and F

• G and H

Which of the following correctly shows how the wires are connected?

• 
• 
• 
• 

The only bulbs that lit up were L2, L3 and L4. Which of the following shows the most likely materials used for each rod?

• 
• 
• 
• 

Which of the following will not be observed when he closes the switch?

• The bulb lights up.

• The steel rod moves towards the iron nail.

• The copper rod remains at the same position.

• Both the steel rod and copper rod will move towards the iron nail.

Which of the following statements is / are true about the circuits?

(You may choose more than one answer)

• Bulbs Q and R are of equal brightness.

• Bulb R is dimmer than Bulb Q.

• Bulb P has the same brightness as bulb Q.

• When Bulb R fuses, the other bulb in its circuit will stay light up.

When one of the bulbs is fused, the other three bulbs will not light up. Which is the bulb that has fused?

• B1

• B2

• B3

• B4

Which of the switches should be closed so that only one bulb in the circuit is able to light up most brightly?

• B and C only

• A, B and C only

• A, B and D only

• B, C and D only

What is the minimum number of switches which need(s) to be closed to light up only two bulbs?

• One

• Two

• Three

• Four