Question

The magnetic intensity $H$ at the centre of a long solenoid carrying a current of $2.0\text{A}$, is found to be $1500{\text{Am}}^{-1}$. Find the number of turns per metre of the solenoid.

• A. $3000$
• B. $1500$
• C. $750$
• D. $500$

Answer 1

The correct option is C $750$

Here,

$H=1500\text{A/m}$, $I=2\text{A}$

We know that magnetic field at the centre of the solenoid is given by,

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

Also, $B={\mu }_{0}H$

$\therefore H=nI$

$\Rightarrow 1500=n\times 2$

$\therefore n=750\text{turns/meter}$

Hence, option $\left(C\right)$ is the correct answer.