Question

The diagram below shows two coils X and Y. The coil X is connected to a battery S and a key K. The coil Y is connected to a galvanometer G

When the key K is closed, State the polarity. 

1. at the end B of the coil X. 

2. at the end C of the coil Y. 

3. at the end C of the coil Y if the coil Y is 

(a) moved towards the coil X, 

(b) moved away from the coil X

Answer 1

1. Current at the end B of coil X is anti-clockwise therefore at this end there is a NORTH pole. 

2. While closing the key, polarity at the end C of the coil Y will be north. There will be no polarity at the end C of the coil Y when the current becomes steady in the coil X. 

3. (a) While the coil Y is moved towards the coil X, the polarity at the end C of the coil Y is NORTH.

(b) While the coil Y is moved away from the coil X, the polarity at the end C of the coil B is SOUTH.