Question
Physics Question on Electromagnetic induction
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
decrease
C
remains same
D
first increase then decrease
Answer
decrease
Explanation
Solution
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 Lenz?? law, the emf induced in the solenoid will oppose this increase, which can be achieved by a decrease in current