Question

The magnetic field at a point on the axis of a long solenoid having $5$ turns per $cm$ length when a current of $ 0.8\,A $ flows through it is

• A. $ 5.024\times 10^{-8} Wb/m^{2}$
• B. $ 6.024\times 10^{-8} Wb/m^{2}$
• C. $ 7.024\times 10^{-8} Wb/m^{2}$
• D. $ 8.024\times 10^{-8} Wb/m^{2}$

Answer 1

Answer: (A)

$B=\mu_{0} n I$
Given, $\mu_{0}=4 \pi \times 10^{-7},$
$n=5\, cm,\, I=0.8\, A$
$B=5.024 \times 10^{-8} Wb / m ^{2}$