Question

If we keep two similar loops made up of copper and constantan in a magnetic field for the same amount of time , in which loop the induced emf will be greater?

Answer 1

Hint: We know that magnetism and electricity are interrelated, the change in one creates a change in flux in the other. When there is a change in magnetic field, this results in the production of electricity, called the induced emf.Given below are the factors which affect the emf .

Complete step-by-step solution:
EMF can either be produced due the change in magnetic field or due to electrochemical reactions which occur in the cell.
Here, since we have two loops which are placed in the magnetic field, we can talk about Faraday's laws of electromagnetic induction.
According to the law, a change in magnetic field induces an emf . Which in turn produces an induced current if the circuit is closed. Also the magnitude of the induced emf is the rate of change of flux linkage .
Since the loop made of copper and constantan are similar, we can say that they have the same area, and also it is given that they are placed in the same magnetic field, hence wil have the same magnetic flux linkage, however copper has higher electrical conductivity as compared to that of constantan.
Thus copper will produce more emf as compared to a constant of similar size which is placed in the same magnetic field.

Note:Electromotive force or emf depends on the area long which the magnetic field passes through and the angle at which the magnetic field lines pass through the given area. Also from Faraday’s laws we know that the emf induced in the coil opposes the rate of change of magnetic flux linked with the coil.