Science 4 · Unit 6: Electricity · Cambridge Primary Science Stage 4

Questions

1. 1. What does a switch do in a circuit?

   • It opens or closes the circuit, to turn it off or on.
   • It makes the electricity stronger.
   • It stores electricity.
   • It makes light.
   Check

2. 2. One circuit has its switch closed, and the other has its switch open. In which should the lamp light up?

   • the circuit with the switch closed
   • the circuit with the switch open
   Check

3. 3. Why should the lamp light up in the circuit with the switch closed?

   • The switch makes its own electricity.
   • The closed switch stops the electricity.
   • The lamp lights without a circuit.
   • The closed switch completes the circuit, so electricity can flow.
   Check

4. 4. How does a switch cause a "break in the circuit"?

   • When it is open, it leaves a gap, so electricity cannot flow.
   • When it is closed, it leaves a gap.
   • It cuts the wires in half.
   • It takes the cell out.
   Check

5. 5. Circuit A has an open switch. Is electricity flowing?

   • Yes
   • No
   Check

6. 6. Circuit A has cells, a lamp and an open switch. Why is no electricity flowing?

   • The wires are too long.
   • The cells are too strong.
   • The lamp is broken.
   • The open switch leaves a gap, so the circuit is not complete.
   Check

7. 7. What must you do to circuit A to make the lamp light up?

   • take out the lamp
   • open the switch
   • take out the cell
   • close the switch
   Check

8. 8. Circuit B has an iron plugged in, with the switch on. Is electricity flowing?

   • Yes
   • No
   Check

9. 9. Circuit B is an iron plugged in and switched on. Why is electricity flowing?

   • The ironing board conducts.
   • The switch is closed, so the circuit is complete.
   • The iron is hot.
   • There is a gap in the circuit.
   Check

10. 10. What must you do to circuit B to turn off the iron?

    • Touch the iron.
    • Close the switch.
    • Open the switch (switch it off).
    • Add another cell.
    Check

11. 11. Which components did Zara and Marcus use in circuit A?

    • a cell, wires, a switch and a lamp
    • two cells, a motor and a switch
    • a cell, wires and a buzzer
    • a lamp and wires only
    Check

12. 12. How do Zara and Marcus know that circuit A is closed?

    • The cell gets heavy.
    • The wires change colour.
    • The lamp goes dark.
    • The lamp lights up.
    Check

13. 13. Zara and Marcus added another cell to make the lamp brighter, but it did not light at all. Why?

    • The second cell was put in the wrong way round.
    • Two cells are too many for one lamp.
    • The switch was closed.
    • The lamp was too bright to see.
    Check

14. 14. How should Zara and Marcus fix circuit B?

    • Turn the second cell round, so + joins −.
    • Add a third cell the same way round.
    • Take out the lamp.
    • Open the switch.
    Check

15. 15. After Zara and Marcus turn the second cell round, how will the lamp compare with the one-cell circuit?

    • It will be the same.
    • It will shine more brightly.
    • It will not light.
    • It will shine less brightly.
    Check