GATE 2020 EE – Question 65
A conducting square loop of side length 1 m is placed at a distance of 1 m from a long straight wire carrying a current $I=2$ A as shown below. The mutual inductance, in nH (rounded off to 2 decimal places), between the conducting loop and the long wire is ________.
Practise this question in The GATE Grind →
Show answer and explanation
Correct answer: 138.10 to 139.20
Explanation
The flux linking the loop is $\Phi=\frac{\mu_0Ia}{2\pi}\ln\frac{d+a}{d}$, so $M=\frac\Phi I=\frac{\mu_0a}{2\pi}\ln\frac{d+a}{d}=2\times10^{-7}\times1\times\ln2=138.6$ nH.