A magnet is dropped through a coil twice: once from just above it, and once from high above it, so it arrives moving faster. Which drop induces the larger EMF at the coil?
Zara pushes a bar magnet into a coil at a steady speed. A meter across the coil reads the induced EMF, and the reading peaks at 0.2 V. Zara wants a bigger peak, without pushing any faster.
One thing she can change is the magnet itself.
Zara swaps the bar magnet for a stronger one. A stronger magnet has a stronger magnetic field.
She pushes the stronger magnet into the same coil at the same steady speed. The reading now peaks at 0.5 V. The stronger magnet induces a bigger EMF.
Why? The stronger magnet's field is stronger everywhere around it. So as the magnet moves, the field through the coil changes by more each second.
A bigger change each second induces a bigger EMF.
The comparison is fair because only one thing changed. Same coil, same speed. Only the magnet is different.
A stronger magnet enters the same coil at the same speed. What happens to the EMF?
A weaker magnet enters the same coil at the same speed. What happens to the EMF?
Quinn pushes a magnet into a coil, and the meter peaks at 0.3 V. He swaps in a weaker magnet and pushes it in at the same speed. Will the new peak be above or below 0.3 V?
The coil and the speed are unchanged; only the magnet's field strength changed.
A weaker field changes the field through the coil by less each second.
A smaller change each second induces a smaller EMF.
The new peak will be below 0.3 V.
A wire is swept between the poles of a magnet, and a small EMF is induced. The magnet is replaced with a much stronger one, and the wire is swept at the same speed. What happens to the EMF?
The wire and its speed are unchanged; only the field strength changed.
The stronger field changes the field around the moving wire by more each second.
A bigger change each second induces a bigger EMF.
The EMF gets bigger.
Asha says that swapping in a stronger magnet, pushed at the same speed, gives a bigger EMF. Is Asha correct?
Mateo wants to test whether a stronger magnet induces a bigger EMF. Which comparison should he make?
A magnet pushed into a coil at 5 cm/s peaks the voltmeter at 0.1 V. A second magnet, pushed into the same coil at 5 cm/s, peaks it at 0.4 V. Which statement explains the larger peak?
A magnet pushed into a coil peaks the voltmeter at 0.4 V. A weaker magnet is pushed in at the same speed. Which peak could the meter show?