Question

A long solenoid has 800 turns per metre length of solenoid. A current of 1.6 A flows through it. The magnetic induction at the end of the solenoid on its axis is

• A. $16 \times 10^{-4} T$
• B. $8 \times 10^{-4} T$
• C. $32 \times 10^{-4} T$
• D. $4 \times 10^{-4} T$

Answer 1

Answer: (B)

$B=\frac{\mu_{0} n I}{2}=\frac{\left(4 \pi \times 10^{-7}\right) \times 800 \times 1.6}{2}$
$=8 \times 10^{-4} T$