Question

The coil in a tangent galvanometer is 16 cm in radius. If a current of 20 MA is to produce a deflection of 45ŗ, then the number of turns wound on it is (take horizontal component

of earth's magnetic field = 0.36 × 10^–4 T and

m₀ = 4p × 10^–7Wb A^–1 m^–1)

• A. 229
• B. 458
• C. 689
• D. 916

Answer 1

Answer: (B)

458

Answer 2

$\frac { \mu _ { 0 } \mathrm { NI } } { 2 \mathrm { R } }$ = B_H tan d