Question

A solenoid is connected to a battery so that a steady current flows through it. If an iron core is inserted into the solenoid, the current will

• A. increase
• B. decreases
• C. remain same
• D. first increases then decreases

Answer 1

The correct option is B decreases

The current will decrease. This is because on inserting an iron core in the
solenoid, the magnetic field increases and hence magnetic flux linked with the solenoid increases. As per Lenzs law, the emf induced in the solenoid will oppose this increase, which can be achieved by a decrease in Current.