Initially, an inductor with no resistance carries a constant current. then the current is brought to a new constant value twice as large. after this change, when the current is constant at its higher value, what has happened to the emf in the inductor? a. it continues to be zero. b.it is larger than before the change by a factor of 4c. it has the same nonzero value. d.it is larger by a factor of 2.e. it has decreased

The emf in the inductor continues to be zero.

Explanation:

It is given that, an inductor with no resistance carries a constant current. Then the current is brought to a new constant value twice as large. Finally, the current is constant at its higher value. We know that the voltage across the inductor is given by :

is the change in current

Since, the change in current is constant, then the emf in the inductor continues to be zero. So, the correct option is (A).