Question

A long solenoid has magnetic field strength of $3.14\times {10}^{-2}T$ inside it when a current of $5A$ passes through it. The number of turns in $1m$ length of the solenoid is

• A. $1000$
• B. $3000$
• C. $5000$
• D. $10000$

Answer 1

The correct option is C $5000$

No of turns per unit length for an infinite solenoid
$n=\frac{B}{{\mu }_{0}i}$
$n=\frac{3.14\times {10}^{-2}}{4\pi \times {10}^{-7}\times 5}=5000$