In the earth inductor experiment what would be the result if

Solution

When the coil with N tunrs rotated in the earth magnetic field ; the change in the magnetic field flux passing thru the coil changes and induces an emf which can be detected by the glavanometer ; when the coil is rotated in 180; the flux changes from 0 to maximum and when the coil is turned from 180 to 360 rotation the flux goes from maxiumum to zero ; for the first 180 rotation the current mesuring needle in galavanometer will show current (due to induced emf )in one direction ; and for the second half rotation of the coil , the direction of the current will changes(due to change in the directio of induced emf) and the needle will deflect to the other side , indicating the reverse in the direction of the current in galavanometer.

The direction of rotation of coil in earth magnetic field either clock wise or counter clock wise direction will determine the initial direction of the current in the glavanometer , which ever the direction the needle move for 0 to 180 rotation ,the next half rotation from 180-360 the direction of the current reverses and in summary we can see that that the needle will make one full oscillation in galvanometer; (if the rotation is in the speed limit such that needle in glavanometer recover its moment of inertia before the coil make second half rotation from 180-360 )