JEE Main202226 Jul 2022Evening ShiftPhysicsMagnetic Effects of CurrentActual
Two concentric circular loops of radii r 1 = 30 cm and r 2 = 50 cm are placed in X - Y plane as shown in the figure. A current I = 7 A is flowing through them in the direction as shown in figure. The net magnetic moment of this system of two circular loops is approximately
Options
- A7 2 k ^   A   m 2
- B- 7 2 k ^   A   m 2
- C7 k ^   A   m 2
- D- 7 k ^   A   m 2
Correct answer
B. - 7 2 k ^   A   m 2
Step-by-step solution
Net magnetic moment of the system is M → = - I A 1 k ^ + I A 2 k ^ (Here currents in both circular loops are in opposite direction) M → = - I π 0 . 5 2 k ^ + I π 0 . 3 2 k ^ M → = - 7 × 22 7 25 100 - 9 100 k ^ = - 22 16 100 k ^ M → = - 3 . 52 k ^   A   m 2 = - 7 2 k ^   A   m 2