JEE Main20199 Jan 2019Morning ShiftPhysicsMagnetic Properties of MatterActual
A bar magnet is demagnetized by inserting it inside a solenoid of length 0.2 m , 100 turns, and carrying a current of 5.2 A . The coercivity of the bar magnet is:
Options
- A285 A / m
- B2600 A / m
- C520 A / m
- D1200 A / m
Correct answer
B. 2600 A / m
Step-by-step solution
Coercivity = n I = 100 0.2 × 5.2     A / m = 2600   A / m