Question

Due to 10 Amp of current flowing in a circular coil of 10 cm radius, the mag. field produced at its centre is π × 10^–3 Tesla. The number of turns in the coil will be 

(a) 5000 

(b) 100 

(c) 50 

(d) 25

Answer 1

The correct option (c) 50

Explanation:

B = [(Nμ₀I)/(2a)]

given: I = 10A

a = 10cm = 10 × 10^–2 m

B = π × 10^–3

∴  π × 10^–3 = N × [(4π × 10^–7 × 10)/(2 × 10 × 10^–2)]

∴  10^–3 = [(N × 4 × 10^–6)/(2 × 10^–1)]

∴   N = [(2 × 10^–4)/(4 × 10^–6)] = 50