Physics · Electromagnetic induction: Faraday's law, induced emf and current, Lenz's law, eddy currents, self and mutual inductance
A metal ring kept (supported by a card board) on the top of a fixed solenoid car
A metal ring kept (supported by a card board) on the top of a fixed solenoid carry a current I as shown in figure. The centre of the ring coincides with the axis of the solenoid. If the current in the solenoid is switched off, then
- A. magnetic flux linked with the metal ring increases.
- B. current induced in the metal ring in clockwise direction
- C. metal ring will not remain on the cardboard
- D. both (a) and (b) are correct
Step-by-step solution
When the solenoid current is switched off, the magnetic flux through the ring decreases. Lenz's law induces a current in the ring to oppose the change. The induced current creates a magnetic field that repels the ring from the solenoid, causing it to lift off the cardboard.
Related MCQs
- Magnitude of e.m.f. produced in a coil when a magnet is inserted into it does not depend upon:…
- A current is induced in a coil by electromagnetic induction.…
- A dynamo produces an electric current. It is based on the principle:…
- The diagram below show a coil connected to a centre zero galvanometer The galvanometer shows a deflection to the right when the -pole of a p…
- The transformer voltage induced in the secondary coil of a transformer is mainly due to:…