A conducting circular loop is placed in a uniform magnetic field of 0.4 T with its plane perpendicular to the field. Somehow, the radius of the loop…

A conducting circular loop is placed in a uniform magnetic field of $\displaystyle 0.4$ T with its plane perpendicular to the field. Somehow, the radius of the loop starts expanding at a constant rate of $\displaystyle 1 \mathrm{~mm} / \mathrm{s}$. The magnitude of induced emf in the loop at an instant when the radius of the loop is $\displaystyle 2$ cm will be $\displaystyle \_\_\_\_$ $\displaystyle \mu \mathrm{V}$.