A conducting circular loop is placed in a uniform field of $B=0.05\;T$ with its plane perpendicular to the loop. The radius of loop is made to shrink at constant rate of $0.5\;mm$ per second. The induced emf when radius is $2 \;cm$ is

Question

$(a)\;1 \times 10^{-6} \pi V \\ (b)\;2 \times 10^{-3} \pi V \\(c)\;1 \times 10^{-6} V \\(d)\;2 \times 10^{-3} V$