A uniform magnetic field is restricted within a region
of radius r. The magnetic field changes with time
at a rate ``\frac {\vec {db}}{dt}``. Loop 1 of radius R > r encloses the
region r and loop 2 of radius R is outside the region
of magnetic field as shown in the figure below. Then
the e.m.f. generated is :-

(1)``-\frac {\vec {db}}{dt}````\pi R^2`` in loop 1 and zero in loop 2
(2) ``-\frac {\vec {db}}{dt}````\pi r^2`` in loop 1 and zero in loop 2
(3) Zero in loop 1 and zero in loop 2
(4) ``-\frac {\vec {db}}{dt}````\pi r^2`` in loop 1 and ``-\frac {\vec {db}}{dt}````\pi r^2`` in loop 2.