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
$\left(\because B={\mu }_{0}nI\right)$