AP EAMCET202316 May 2023Evening ShiftPhysicsMagnetic Effects of CurrentActual
A circular coil of 30 turns and radius 8 ~cm carrying a current of 6 ~A is suspe-ded vertically in a uniform horizontal magnetic field of magnitude 1.0 ~T . The field lines make an angle of 20^ with the normal of the coil. The magnitude of the counter torque that must be applied to prevent the coil from turning is
Options
- A5.4 Nm
- B7.2 Nm
- C3.6 Nm
- D1.8 Nm
Correct answer
D. 1.8 Nm
Step-by-step solution
Number of turns, N =30 turns Radius, r =8 ~cm =0.08 ~m Current, i =6 ~A Magnetic field, B =1 ~T The magnitude of the counter tarque will be aligned & = NiAB & = N i r ^2 ~B 30^ & =30 6 3.14 (0.08)^2 1 1 2 & =1.8 Nm aligned