The coil in a tangent galvanometer is 16 cm in radius. If a current of 20 mA is to produce a deflection of 45º, then the number of turns wound on it is (take horizontal component of earth's magnetic field = 0.36 × 10–4 T and μ0 = 4π × 10–7 Wb A–1 m –1 )
(A) 229
(B) 458
(C) 689
(D) 916
