A solenoid of length 15 cm has 60 turns. Find the current required to produce a magnetic field intensity H = 2.4 × 10³ A m⁻¹ for demagnetizing a bar magnet.
Physics · Circular Motion
JEE Mains 10 April 2023 Shift 1 Morning Shift

Question

A solenoid of length 15 cm has 60 turns. Find the current required to produce a magnetic field intensity H = 2.4 × 10³ A m⁻¹ for demagnetizing a bar magnet.

G1 Physics · Accepted Answer

For a long solenoid, H = nI = (N/l)I Therefore, I = Hl/N Given: H = 2.4×10³ A m⁻¹ l = 15 cm = 0.15 m N = 60 So, I = (2.4×10³)(0.15)/60 = 6 A Final value: 6