Question

A tangent galvanometer has a coil of 50 turns and a radius of 20 cm. The horizontal components of the earth's magnetic field isB_H = 3 × 10^–5 T, the current which gives the deflection of 45° is-

• A. 0.12 A
• B. 0.19 A
• C. 0.32 A
• D. 0.21 A

Answer 1

Answer: (B)

0.19 A

Answer 2

i = K tan q

= tan q

= $\frac { 2 \times 0.2 \times 3 \times 10 ^ { - 5 } } { 4 \pi \times 10 ^ { - 7 } \times 50 }$ tan 45^` = 0.19 A