Question

In this section each equation has some statements (A, B, C, D …….) given in column-I and some statements (P, Q, R, S, T, ……) in column-II. Any given statement in column-I can have correct matching with ONE OR MORE statements (s) in column-II. 

The physical quantities are given in column-I and their various related factors in column-II.

column - I	column - II
(A) Torque on a coil carrying current when held in a mag. field.	(P) Restoring torque per unit twist of the suspension strip (K).
(B) current sensitivity of galvanometer	(Q) Number of turns in the coil(N)
(C) Voltage sensitivity of galvanometer	(R) Magnetic field (B)
(D) figure of merit of galvanometer	(S) Area of the coil (A)

Answer 1

Explanation:

(A) → Q, R, S 

(B) → P, Q, R, S 

(C) → P, Q, R, S 

(D) → P, Q, R, S

(A) Torque on a coil = τ = BINA cosθ 

hence τ is function of B, N, A.

(B) I_s = current sensitivity of galvanometer = [(NBA)/K] hence Is is function of N, B, A, K.

(C) V_S = Voltage sensitivity of galvanometer = [(NBA)/KR] hence V_s is function of N, B, A, K. 

(D) Figure of merit of galvanometer = [1/(current sensitivity)] = [K/(NBA)] i.e. it is function of N, B, A, K.