Question

Why galvanometer shows opposite deflection in potentiometer?

Answer 1

Galvanometer shows opposite deflection in potentiometer because of the following reasons :
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 ends of all cells are not connected to the same end of the wire.
3.  if the potential difference is zero, no current flows through the galvanometer and the needle remains in its zero position.