Question Constellation Sign up for free AQA · GCSE · Physics · Higher
Reversing Electromagnet Force
Figure 7 shows an electromagnet close to a permanent magnet.
Give two changes to the electromagnet that would reverse the direction of the force exerted on the permanent magnet.
Write your answer first. You can study the marking guidance whenever you need it.
Study the marking See what earns credit and compare it with a full-mark answer.
Marking points
- 1 Gives a first valid reversal change: reverse current, turn the electromagnet around, or wind the coil in the opposite direction.
- 2 Gives a second distinct valid change from the official alternatives.
Full-mark answer
1. Reverse the direction of current through the coil. 2. Turn the electromagnet around so its poles are reversed.
Why this answer loses marks
Decrease the current and move the magnets apart.
These changes reduce force but do not reverse the electromagnet's poles. The current direction, electromagnet orientation, or winding direction must be reversed.