Question

In a tangent galvanometer a current of 0.1 A produces a deflection of 30° . The current required to produce a deflection of 60° is

• A. (a) 0.2 A
• A. (b) 0.3 A
• A. (c) 0.4 A
• A. (d) 0.5 A

Answer 1

(b)

Sol. $i \propto \tan \phi \Rightarrow \frac { i _ { 1 } } { i _ { 2 } } = \frac { \tan \phi _ { 1 } } { \tan \phi _ { 2 } }$

$\Rightarrow \frac { 0.1 } { i _ { 2 } } = \frac { \tan 30 ^ { \circ } } { \tan 60 ^ { \circ } } = \frac { 1 } { 3 } \Rightarrow i _ { 2 } = 0.3 \mathrm {~A}$