Question

The self inductance of a coil having 500 turns is $50\, mH$. The magnetic flux through the cross-sectional area of the coil while current through it is $8\, mA$ is found to be

• A. $ 40 \times 10^{-4}$ Wb
• B. $0.04$ Wb
• C. $4\, \mu Wb$
• D. $40\, m Wb$

Answer 1

Answer: (A)

Given, $n=500$
$L =50 \,mH =50 \times 10^{-3} H $
and $ i =8 \,mA =8 \times 10^{-3} A$
The magnetic flux linked with the coil is
$\phi =L i=50 \times 10^{-3} \times 8 \times 10^{-3} $
$=400 \times 10^{-6}=4 \times 10^{-4} Wb .$