Question

A closely wound coil of `100` turns and area of cross-section `1cm^(3)` has a coefficient of self-induction `1 mH`. The magnetic induction in the centre of the core of the coil when a current of `2A` flows in it, will be
A. `0.022 Wb m^(-2)`
B. `0.4 Wb m^(-2)`
C. `0.8 Wb M^(-2)`
D. `1 Wb m^(-2)`

Answer 1

Correct Answer - A
`B=(mu_(0)Ni)/(2r)=(4pixx10^(-7)xx100xx2xxsqrt(pi))/(2xx10^(-2))=(0.002 wb//m^(2)`