Question

In the moving coil galvanometer
N= number of turns; A= cross sectional area; B= Magnetic field; C= Torsional constant; I= current, R= resistance

List I		List II
(P)	Torque action on the coil	(1)	NAB /C
(Q)	Deflection produced	(2)	NAB/CR
(R)	Current sensitivity	(3)	NIAB
(S)	Voltage sensitivity	(4)	NABI/C

• A. P- 3, Q- 1, R- 2, S- 4
• B. P- 2, Q- 1, R- 3, S- 4
• C. P- 3, Q- 4, R- 1, S- 2
• D. P- 4, Q- 1, R- 2, S- 3

Answer 1

The correct option is C P- 3, Q- 4, R- 1, S- 2

Here,

Torque=\overrightarrow p\times B$

$\tau =IABN$

$P\to 3$

Also,

$\tau =c\theta$

Where, c=torsional constant,

$\theta =\frac{NIAB}{c}$

$Q\to 4$

Current sensitivity=$\frac{\theta }{I}$

$=\frac{NAB}{c}$

$R\to 1$

Voltage sensitivity=$\frac{\text{Current sensitivity}}{R}$

$=\frac{NAB}{cR}$

$S\to 2$