Two concentric circular loops of radii r₁ = 30 cm and r₂ = 50 cm are placed in X-Y plane as shown in the figure. A current I = 7A is flowing through them in the direction as shown in figure. The net magnetic moment of this system of two circular loops is approximately :

see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

$- \frac{7}{2} \hat{k} {Am}^{2}$

$7 \hat{k} {Am}^{2}$

$- 7 \hat{k} {Am}^{2}$

$\frac{7}{2} \hat{k} {Am}^{2}$

answer is B.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

Magnetic moment

$\begin{array}{l} \vec{M} = - iπ (0 .5)^{2} \hat{k} + iπ (0 .3)^{2} \hat{k} \\ \vec{M} = - 7 \times \frac{22}{7} (\frac{25}{100} - \frac{9}{100}) \hat{k} \\ = - 22 (\frac{16}{100}) \hat{k} \\ \vec{M} = - 3 .52 \hat{k} {Am}^{2} \\ = - \frac{7}{2} \hat{k} {Am}^{2} \end{array}$