JEE Main 202310 AprilEvening Shift
- Exam
- JEE Main
- Year
- 2023
- Date
- 10 April
- Shift
- Evening Shift
- Subject
- Physics
- Chapter
- Magnetic Properties of Matter
JEE Main 2023 · 10 April · Evening Shift · Physics · Magnetic Properties of Matter
A bar magnet is released from rest along the axis of a very long...
A bar magnet is released from rest along the axis of a very long vertical copper tube. After some time the magnet will
Options
- AMove down with an acceleration equal to
- BOscillate inside the tube
- CMove down with almost constant speed
- DMove down with an acceleration greater than
Correct answer
C. Move down with almost constant speed
Step-by-step solution
The flux connected to the copper tube will fluctuate when the magnet moves under the influence of gravity. Eddy currents will be created in the copper tube's body as a result, these induced currents oppose the collapse of the magnet, in accordance with Lenz's law.
A retarding force will consequently act on the magnet. This force will keep rising with the magnet's rising velocity until it equals the force of gravity. The net force acting on the magnet will then vanish. The magnet will therefore reach a steady speed.