Q7 of 32 Page 98

In the arrangement shown in Figure 13.4 there are two coils wound on a non-conducting cylindrical rod. Initially the key is not inserted. Then the key is inserted and later removed. Then

In the given figure, when electric current through first coil changes then due to change in magnetic field lines, there will be an EMF (electromotive force) induced in the another coil. When the key is inserted in the circuit and when it is removed, the magnetic field lines will be first increase and then decreases. So, the current will be in opposite directions in the two cases, therefore, there are momentary galvanometer deflections in opposite directions.

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