Question

In above shown figure, a long straight wire that carries $I$ upward create a magnetic field. If a small circular loop shown in figure is moving from distance $x_2$ to distance $x_1$ from the straight wire, what will be the direction of the induced current in the loop and the direction of the corresponding magnetic field it produces?

• A. The induced current will be clockwise, and the magnetic field it produces will point out of the plane of the page
• B. The induced current will be clockwise, and the magnetic field it produces will point into the plane of the page
• C. The induced current will be counterclockwise, and the magnetic field it produces will point out of the plane of the page
• D. The induced current will be counterclockwise, and the magnetic field it produces will point into the plane of the page.
• E. None of the above

Answer 1

The correct option is C The induced current will be counterclockwise, and the magnetic field it produces will point out of the plane of the page

The direction of magnetic field inside the ring due to straight current carrying wire will be inward the plane of paper ( by right hand thumb rule) when loop moves towards wire magnetic flux linked with loop changes and current is induced in loop ,now by Lenz's law the direction of induced current in loop will be such that the magnetic field due to induced current opposes the magnetic field due to wire and that will happen when induced current is counterclockwise , hence magnetic field's direction will point out of the plane of paper(opposite to the magnetic field direction of wire)