Asked by Shubham Jain | 22nd Nov, 2014, 04:27: PM

Expert Answer:

The possible causes for the one sided deflection in the galvanometer during potentiometer experiment can be:

1. The potential difference between the ends of the potentiometer wire or the emf of the cell connected in the main circuit may not be greater than the emf of the cells whose emf are to be compared .
2. The positive terminals of the cells and the battery used in the circuit might not be connected to the same end of the potentiometer wire.
3.The rheostat might not be adjusted properly and kept in such a position that it offers minimum resistance to the circuit and allows maximum current through the wire.
 
If your circuit is not properly connected then you will not obtain the null point, it will show one sided deflection in the galvanometer which can be due to the above stated causes.
When you find difficulty in getting the null point i.e. if you obtain one sided deflection on placing the jockey at two ends of the potentiometer wire it means that you have made some mistake in the circuit connection. In such cases ensure your connections, check if all connections are tight and connecting wires are not broken also check if you have taken care of the above stated causes.

Answered by Jyothi Nair | 22nd Nov, 2014, 11:38: PM