Electrical Systems - Conductors & Insulators

Material W, X and Y is connected to an electric circuit one at a time, as shown in the diagram below.
Which of the following could materials W, X and Y be?

• W – ceramic
  X – cloth
  Y - Iron
• W – Steel
  X – glass
  Y - plastic
• W – aluminium
  X – copper
  Y - rubber
• W – iron
  X – copper
  Y - gold

Which of the following objects, when placed in a closed circuit, will cause the bulb to light up?

A: Copper wire  B: Plastic ruler
C: Wooden chopsticks   D: Iron nail

• A and B only
• C and D only
• A and D only 
• B and C only

Max tested some objects with the circuit tester. Then, he recorded his results in the table below.

Based on his results, which of the following conclusions is the most likely to be true?

• A, B and C are flexible objects.
• B is a non-conductor of electricity.
• A is made of iron and B is made of copper.
• Conductors of electricity are also heat conductors.

When the circuit shown is closed, none of the bulb lights up in the circuit above. Only one of the objects, A, B or C is an electrical insulator. Which one is it?

• A
• B
• C

James set up 3 similar circuits as shown. P, Q and R are made of different materials. James made some observations in the table. Which of the following statements about the above observations is correct?

• R is made of wood.
• P is a conductor of electricity.
• Q is a conductor of electricity.
• P is a better conductor of electricity compared to Q. 

P, Q and R are objects placed in the circuit shown below. A, B and C are switches. The table below shows what happens when the switches are closed.
Based on the results above, which of the objects P, Q or R is a conductor of electricity?

• P and Q only
• P and R only
• Q and S only
• P, Q and R

Study the circuit below. When the switch was closed, three of the bulbs, B1, B3 and B4, lighted up while B2 did not. Which object(s) is/are conductor(s) of electricity?

• Z and X only
• Y and X only
• Y and Z only
• X, Y and Z 

Study the circuit diagram below. 
When the switch was closed, all the bulbs lighted up. Then, when one of the bulbs fused, all the bulbs went off. Which bulb was fused?

• A
• B
• C
• D

Study the circuit. For all the bulbs to be lighted up, what is the minimum number of electrical conductors that can be placed at A, B, C and D?

• 1
• 2
• 3
• 4

When an electrical insulator is placed in the circuit, the circuit is ___________ as there is a _________ in the circuit.

• open... open
• closed... open 
• open... break 
• closed... break