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Boss quiz

10 questions on the whole topic. You get one try at each.

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  1. What are the two poles of a magnet called?

    • Top and bottom
    • Positive and negative
    • North and south
    • East and west

  2. Two north poles are brought close together. What happens?

    • They attract
    • Nothing happens
    • They repel
    • They stick together

  3. Which of these is a magnetic material?

    • Plastic
    • Steel
    • Copper
    • Aluminium

  4. Which way do the arrows on the field lines round a bar magnet point?

    • Straight out from both poles
    • In circles round the middle of the magnet
    • From the north pole to the south pole
    • From the south pole to the north pole

  5. Where is the field of a bar magnet strongest?

    • At the middle of the magnet
    • At its poles
    • Far away from the magnet
    • It is the same everywhere

  6. Why does a compass needle point north?

    • It is pulled by the Earth’s gravity
    • It is a magnet that lines up with the Earth’s magnetic field
    • It follows the Sun
    • It is pushed round by the wind

  7. Which of these makes an electromagnet?

    • A bar magnet and a compass
    • A coil of wire with no current in it
    • A plastic rod and a cell
    • A coil of wire with a current in it, round an iron core

  8. Which change makes an electromagnet stronger?

    • More turns on the coil
    • Taking out the iron core
    • Fewer turns on the coil
    • A smaller current

  9. Why does a scrapyard crane use an electromagnet and not a permanent magnet?

    • It can be switched off to drop the load
    • It attracts every kind of metal
    • It is magnetic all the time
    • It needs no electricity

  10. What makes the coil in an electric motor spin?

    • A current in the coil, which sits between the poles of a magnet
    • Gravity pulling one side of the coil down
    • Air blowing through the motor
    • Heat from the wires
Answers
  1. North and south. Every magnet has a north pole and a south pole.
  2. They repel. Like poles repel. Unlike poles attract.
  3. Steel. Iron, steel, nickel and cobalt are magnetic materials.
  4. From the north pole to the south pole. Field lines run from the north pole round to the south pole.
  5. At its poles. The field lines are closest together at the poles. That shows the field is strongest there.
  6. It is a magnet that lines up with the Earth’s magnetic field. The Earth has a magnetic field. The needle is a small magnet that can turn freely, so it lines up with that field.
  7. A coil of wire with a current in it, round an iron core. A current in the coil makes a magnetic field. The iron core makes it much stronger.
  8. More turns on the coil. More turns, a bigger current and an iron core all make an electromagnet stronger.
  9. It can be switched off to drop the load. An electromagnet lets go when its current is switched off. A permanent magnet cannot be switched off.
  10. A current in the coil, which sits between the poles of a magnet. The current makes the coil an electromagnet. The magnet pushes and pulls on it, so it turns.