Question

In a tangent galvanometer, a current of 1A produces a deflection of 30?. The current required to produce a deflection of 60? is

• A. 3A
• B. 2A
• C. 4A
• D. 1A

Answer 1

The Correct Option is A

Current in tangent galvanometer
$I=\frac{H}{G}tan\theta$
Where G = galvanometer constant
H= earth's horizontal field = constant
$\therefore \frac{I_1}{I_2}=\frac{tan\theta_1}{tan\theta_2} \Rightarrow \frac{I}{I_2}=\frac{tan30^{\circ}}{tan60^{\circ}}$
$\Rightarrow I_2 = \frac{tan60^{\circ}}{tan30^{\circ}}=\frac{1.7321}{0.5774}=2.999 \dot{A}$
$\Rightarrow I_2=3A$