NEET2026PhysicsChapterActual
A rectangular coil of 2500 turns and dimensions 80 cm 50 cm is rotated at a constant angular speed of 200 rad s ⁻¹ about its vertical axis of symmetry. At this location, the horizontal component of the earth's magnetic field is 3 10⁻⁵ T and the vertical component is 4 10⁻⁵ T . If the electrical resistance of the coil is 2 , what will be the maximum induced current in the coil?
Options
- A4 A
- B5 A
- C3 A
- D1.5 A
Correct answer
C. 3 A
Step-by-step solution
Since the coil is rotated about its vertical axis of symmetry, its area vector always lies in the horizontal plane. Therefore, the vertical component of the earth's magnetic field ( B_V ) is always parallel to the plane of the coil and does not contribute to the magnetic flux. Only the horizontal component ( B_H ) contributes to the changing magnetic flux. The maximum induced EMF in the coil is given by: E_ max = N A B_H Given values: N = 2500 A = 80 cm 50 cm = 0.8 m 0.5 m = 0.4 m ^2 B_H = 3 10⁻⁵ T = 200 rad s ⁻¹ S