Question

A soft iron bar is inserted inside a current-carrying solenoid. The magnetic field inside the solenoid :

(a) will decrease (b) will increase

(c) will become zero (d) will remain the same

Answer 1

(b) Will increase

When current carrying solenoid is taken, it produces its own magnetic field inside and outside the solenoid. When a soft iron bar/core is placed inside the solenoid, it magnetizes the iron bar thereby increasing the strength of the magnetic field inside the solenoid.