Question

In a straight conducting wire, a constant current is flowing from left to right due to a source of emf when the source is switched off, the direction of the induced current in the wire will be ?

Answer 1

In order to solve this question, we will have to understand the definition of emf which stands for electromotive force. It is that force which develops due to potential difference it causes electrons motion and constitutes current in wire. Current is defined as the number of charges flowing per unit time in a unit cross sectional area. Also emf is induced in wire whenever there is net change in flux through wire and it develops according to Lenz law.

Complete answer:
As we know, electromotive force induced in any loop whenever there is change in magnetic flux and hence current flows but its direction is determined from Lenz’s law which states that current induced will flow in such direction so as to oppose the cause of its generation just like a body opposes to change its state known as inertia.

So when emf provides current from left to right current induced gets comfortable in flowing suddenly due to stopping of source emf current starts to decrease so according to Lenz’s law current opposes this behavior and thus try to increase So its start flowing from left to right so that net current increases.

So the right answer is current starts flowing from left to right.

Note: It should be remembered that flux through any loop could be changed by three methods in which first is by changing magnetic field, second is by changing area under magnetic field and third is by changing orientation of loop thereby changing flux. So the loop always tries to oppose this change in flux and hence current and its direction are determined from Lenz law.