Question

State Lenz’s law. A metallic rod held horizontally along east-west directions is allowed to fall gravity. Will there be an emf induced at its ends? Justify your answer.

Answer 1

Hint: German physicist Heinrich Friedrich Lenz deduced a rule, known as Lenz’s law which gives the polarity of the induced emf in a clear and a concise fashion. If the current arises in the coil then the magnetic fields will increase.

Complete step by step solution:
The direction of the current is in such a way that the current produced by it opposes the change of an external flux it is called as Lenz law. The pole of magnet through the coil induces an electric current. This current in turn up will give the magnetic field around the coil.

Then the Lenz law indicates the direction of the induced current. In Lenz law the North-pole is approaching the coil, so that the induced current will flow around the coil. If we withdraw the magnet from the coil, the induced current will reverse because the South-pole is produced to attract the force on the reducing bar magnet.

The small amount of work is done by the magnet into the coil and it is pulled against the magnetic effect of induced current. Lenz law works on the principle of conservation of energy. Yes, Emf can be induced in the rod where there is a change in the magnetic flux.

If the metal rod is held horizontally in East – West direction is allowed to fall free under a gravity. If fall in the form of North to South the magnetic flux is changed and the emf is also induced in it.

Note: Lenz law can understand the stored magnetic energy in an indicator. Lenz law balances the eddy current and eddy current dynamometer. If the emf is connected to an inductor, then the current starts flowing through the coil. The back emf will increase the current through the indicator. In lens law voltage can create only by changing the magnetic flux.