Question

A long solenoid with $500$ turns per unit length carries a current of $1.5 \,A$. The magnetic induction at one of the ends of the solenoid on its axis is nearly

• A. $32 \times 10^{-4}$T
• B. $4 \times 10^{-5}$T
• C. $47 \times 10^{-5}$T
• D. $16 \times 10^{-4}$T
• E. $ 8 \times 10^{-5} $T

Answer 1

Answer: (C)

$B=\frac{\mu_{0} \,n i}{2}=\frac{4 \pi \times 10^{-7} \times 500 \times 1.5}{2}=47 \times 10^{-5} \,J$