JEE Advanced2010PhysicsMagnetic Effects of CurrentActual
A thin flexible wire of length L is connected to two adjacent fixed points and carries a current I in the clockwise direction, as shown in the figure. When the system is put in a uniform magnetic field of strength B going into the plane of the paper, the wire takes the shape of a circle. The tension in the wire is
Options
- AI B L
- BI B L
- CI B L 2
- DI B L 4
Correct answer
C. I B L 2
Step-by-step solution
L=2 RR= L 2 2 T (d )=F_m for small angles, (d ) d aligned 2 T(d ) & =I(d L) B 90^ & =I(2 R d ) B T & =I R B= I L B 2 aligned correct option is (c)