Question

Two concentric circular loops of radii 0.08m and 0.1 m carries current such that magnetic field at the center is zero. If the current in the outer loop is 8A clockwise, current in the inner loop is :-

• A. 6.4 A anticlockwise
• B. 6.4 A clockwise
• C. 8A anticlockwise
• D. 3.2 A clockwise

Answer 1

The correct option is A 6.4 A anticlockwise

$\left|B_1\right|=\left|B_2\right|$

$\left|\frac{{\mu }_0{I}_1}{2r_1}\right|=\left|\frac{{\mu }_0{I}_2}{2r_2}\right|$

$\frac{8}{0.1}=\frac{I_2}{0.08}$

$I_2=6.4A$ (Anti clockwise)