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

Answer

C

Explanation

(c ) In balance condition, no current will flow through the brach containing `S`.