Question

Consider the following statements:
(A) An emf can be induced by moving a conductor in a magnetic field.
(B) An emf can be induced by changing the magnetic field.

(a) Both A and B are true.
(b) A is true but B is false.
(c) B is true but A is false.
(d) Both A and B are false.

Answer 1

(a) Both A and B are true.

Statement A is true, as an emf can be induced by moving a conductor with some velocity v in a magnetic field B. It is given by
$e=Bvl$

Statement B is true, as an emf can be induced by changing the magnetic field that causes the change in flux ϕ through a conductor or a loop. It is given by
$e=-\frac{d\varphi }{dt}$