Question

A long solenoid has $1000$ turns per meter length of solenoid. A current of $3.2 A$ flow through it. The magnetic induction at the end of solenoid is

• A. $2 \times 10^{-3} \,T$
• B. $8 \times 10^{-4} \, T$
• C. $8 \times 10^{-3} \, T$
• D. $2 \times 10^{-4} \,T$

Answer 1

Answer: (A)

$B_{\text {end }} =\frac{\mu_{0} \,n I}{2} $
$=\frac{4 \pi \times 10^{-7} \times 1000 \times 3.2}{2} $
$=2 \times 10^{-3} \,T$