Question

A solenoid of 1.5 metre length and 4.0 cm diameter possesses 10 turns per cm. A current of 5 ampere is flowing through it. The magnetic induction at axis inside the solenoid is –

• A. 2p × 10^–3 T
• B. 2p × 10^–5 T
• C. 2p × 10^–2 gauss
• D. 2p × 10^–5 gauss

Answer 1

Answer: (A)

2p × 10^–3 T

Answer 2

For solenoid B = m₀ni = 4p × 10^–7 × $\frac { 10 } { 10 ^ { - 2 } } \times 5$

= 2p × 10^–3 T