10 minutes maximum! Can you do it in 5?

1. A copper wire has a magnetic field around it if...

• A. it has been magnetised.
• B. there is a current flowing through it.
• C. it is twisted into a coil.
• D. it is heated up.

Q 2-4. The diagram below shows a copper wire between 2 magnets.

2. In which direction is the magnetic field?

• A. N to S
• B. S to N
• C. A to B
• D. B to A

3. A current flows through the wire from A to B. Which way is the wire pushed?

• A. To the right
• B. To the left.
• C. Upwards.
• D. Downwards.

4. If we want the force on the wire to be reversed, which way must current flow?

• A. N to S
• B. S to N
• C. A to B
• D. B to A

5. If we want the wire to be pushed to the right, which way must current flow?

• A. A to B
• B. B to A
• C. Use an alternating current.
• D. This is not possible using a current.

6. Using the left-hand rule, what represents the magnetic field?

• A. Thumb.
• B. First finger.
• C. Second finger.
• D. Third finger.

7. In which direction will this wire be pushed?

• A. To the left.
• B. To the right.
• C. Upwards.
• D. Downwards.

8. There are several ways to increase the size of the force on the wire. Which of these will not work?

• A. use a wire with less mass.
• B. Increase the current.
• C. Increase the strength of the magnetic field.
• D. Increase the length of wire in the field.

9. What could be done to push the wire in the opposite direction, with twice the force?

• A. Switch the N and S poles of the magnets round.
• B. Double the current.
• C. Switch the direction of the current AND the N and S poles.
• D. Double the current AND switch the N and S poles.

10. This coil of wire has a current flowing through it which makes the coil move.

Which way does the coil move?

• A. To the left.
• B. To the right.
• C. Rotates clockwise.
• D. Rotates anti-clockwise.