Question

A very long solenoid has $800$ turns per metre length of the solenoid. A current of $1.6A$ flows through it. Then the magnetic induction at the middle point of the solenoid on its axis is approximately.

• 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

The correct option is A $16\times {10}^{-4}T$

The magnetic induction at the middle point of the solenoid on its axis is given as,

$B={\mu }_{0}nI$

$=4\pi \times {10}^{-7}\times 800\times 1.6$

$=16.084\times {10}^{-4}T$

Thus, the magnetic induction is $16.084\times {10}^{-4}T$.