AP EAMCET201920 Apr 2019Evening ShiftPhysicsMagnetic Effects of CurrentActual
A coil in the shape of an equilateral triangle of side 2 ~cm is suspended from a vertex such that it hangs in a vertical plane between the poles of a permanent magnet producing a horizontal magnetic field of 100 10⁻³ ~T . The magnetic field is parallel to the plane of the coil. For the moment of couple acting on the coil to be 2 3 10⁻⁵ Nm , the current to be passed through the coil is
Options
- A0.5 A
- B1 A
- C2 A
- D4 A
Correct answer
C. 2 A
Step-by-step solution
Given, magnetic field, B=100 10⁻³ ~T Torque, =2 3 10⁻⁵ Nm Now, torque =M B=I A B where, M= magnetic dipole moment, B= magnetic field I= current to be passed through the coil. Putting the given values in above expression, 2 3 10⁻⁵=I 3 10⁻⁴ 100 10⁻³ or I=2 ~A