Question

A conducting loop in the form of a circle is placed in a uniform magnetic field with its plane perpendicular to the direction of the field. An e.m.f. will be induced in the loop if

• A. I is translated parallel to itself.
• B. It is rotated about one of its diameters.
• C. It is rotated about its own axis which is parallel to the field.
• D. The loop is deformed from the original shape.

Answer 1

Answer: (B), (D)

The correct options are
B It is rotated about one of its diameters.
D The loop is deformed from the original shape.

The EMF induced in a loop is given as $EMF=-\frac{d\varphi }{dt}$

Hence a change in flux through the loop is necessary for emf induction, which happens only in case of options B and D.

Hence correct answers are options B and D.