Question

A long solenoid of length $ L $ has a mean diameter $ D $ , It has n layers of winding of $ N $ turns each. If it carries a current $ I $ , the magnetic field at its centre will be

• A. proportional to $ D $
• B. inversely proportional to $ D $
• C. independent of $ D $
• D. proportional to $ L $

Answer 1

Answer: (C)

Magnetic field due to solenoid is independent of diameter
$\left(\because B=\mu_{0} n I\right)$