Question

The radius of the coil of a Tangent galvanometer. Which has 10 turns is 0.1m. The current required to produce a deflection of 60° is

• A. (a) 3 A
• A. (b) 1.1 A
• A. (c) 2.1 A
• A. (d) 1.5 A

Answer 1

(b)

Sol. $B = B _ { H } \tan \theta$ ⇒ $\frac { \mu _ { 0 } n i } { 2 r } = B _ { H } \tan \theta$

⇒ $= \frac { 2 \times 0.1 \times 4 \times 10 ^ { - 5 } } { 10 \times 4 \pi \times 10 ^ { - 7 } }$ = 1.1A