The firgure shows a circuit diagram of a 'Wheatstone Bridge' to measure the resistance `G` of the galvanometer The relation `(P)/(Q) = (R )/(G)` will be satisfied only when

Options

A. The galvanometer shows a deflection when switch S is closed
B. The galvanometer shows a deflection when switch S is open
C. The galvanometer shows no change in deflection whether S is open or closed
D. The galvanometer shows no deflection

Answer

C

Explanation

This is a balanced bridge, no current flow through the branch containing S.