1. Which of these diagrams shows the magnetic field lines around the north pole of a magnet?

2. Which one of these could not have a magnetic field around it?

  • A). Horseshoe magnet
  • B). Electric cable
  • C). Copper bar
  • D). Compass

3-7. What are the missing words in this passage about the 'motor effect'?

In the diagram shown, a wire has a current flowing though it
and is placed between two magnets. There is
between the north and south poles pointing .
This pushes the wire . If the direction of the current
was reversed, the wire would be pushed . This force
is only produced when the direction of the current is to
the direction of the field lines.

 

8. Which one of these appliances does not use the effect described in the last question?

  • A). Loudspeaker
  • B). Motor
  • C). Light bulb
  • D). Relay

9. The force on a wire can be made stronger in several ways. Which one of these will not work?

  • A). Increase the current
  • B). Use stronger magnets
  • C). Use a coil with many turns
  • D). Make the wires thinner

10. If you push a metal bar quickly between 2 magnets it produces a voltage in the bar. What is this effect called?

  • A). Induction
  • B). Reduction
  • C). Generation
  • D). Production
11. The diagram shows an a.c. generator, made with a coil turning inbetween two magnets. A voltage is produced, which is used to heat a resistor (labelled the load in the diagram).

a.c. generator

  

What would happen if the coil was rotated faster?

  • A). The resistor would stay the same temperature.
  • B). The resistor would take more current but stay the same temperature.
  • C). The voltage and temperture would increase
  • D). The resistor would cool down.

12. Which of these methods will not generate a voltage?

  • A). Rotate a coil in a magnetic field
  • B). Rotate a magnet inside a coil
  • C). Move a magnet past a wire
  • D). Move a wire past a coil

13. A.C. generators are found in ...

  • A). C.D. players
  • B). Phone chargers
  • C). Power stations
  • D). Amplifiers