99 Percentile Qs Bank for JEE MainPhysicsMagnetic Effects of Current
Two circular concentric loops of radii r 1 = 20 cm , r 2 = 30 cm are placed in the X - Y plane as shown in the figure. A current I = 7 A is flowing through them. The magnetic moment of this loop system is
Options
- A+ 0.4 k ^ A m 2
- B- 1.5 k ^ A m 2
- C+ 1.1 k ^ A m 2
- D+ 1.3 j ^ A m 2
Correct answer
C. + 1.1 k ^ A m 2
Step-by-step solution
Here, magnetic moment due to loop 1 M 1 = iA 1 = iπr 1 2 = 7 π 0 .20 2 = 0 .28 π Similarly magnetic moment due to loop- 2 M 2 = iA 2 = iπr 2 2 = 7 π 0 .30 2 = 0 .63 π Net magnetic moment = M 1 - M 2 = 0 .63 π - 0 .28 π = 1 .1 A m 2