Question

Two concentric coils each of radius equal to $2\pi cm$ are placed at right angles to each other. $3$ Ampere and $4$ ampere are the currents flowing in each coil respectively. The magnetic induction in $Weber/m^2$ at the centre of the coils will be (${\mu }_0=4\pi \times {10}^{-7}Wb/A-m$)

• A. $12\times {10}^{-5}$
• B. ${10}^{-5}$
• C. $5\times {10}^{-5}$
• D. $7\times {10}^{-5}$

Answer 1

Answer: (C)

$5\times {10}^{-5}$

$B_{net}=\sqrt{B_1^2+B_2^2}=\frac{{\mu }_0}{4\pi }.\frac{2\pi }{r}\sqrt{i_1^2+i_2^2}$
$={10}^{-7}\times \frac{2\pi }{2\pi \times {10}^{-2}}\sqrt{(3{)}^2+(4{)}^2}=5\times {10}^{-5}wb/m^2$