Question

Ansari Sir was demonstrating an experiment in his class with the setup as shown in the figure below.

A magnet is attached to a spring. The magnet can go in and out of the stationary coil. He lifted the Magnet and released it to make it oscillate through the coil.
Based on your understanding of the phenomenon, answer the following question.

Is there any difference in the observations in the galvanometer when the Magnet swings in and then out of the stationary coil? Justify your answer.

Answer 1

• When the magnet moves into the coil, the ammeter shows a momentary deflection towards one side saying left.
• When the magnet moves out of the coil, the ammeter shows a momentary deflection now towards right.
• This is due to changing magnetic field/flux associated with the coil as the magnet moves in and out.
• Alternatively, the flux increases when the magnet goes in and it decreases when the magnet goes out.