A 0.40m long rod is moved in a uniform magnetic field of 0.50T such that its velocity is always perpendicular to the field. If the speed of the rod varies with time as v(t)=2tm s−1 (with t in seconds), what is the emf induced at t=4s?
(a) 4.00V
(b) 1.60V
(c) 0.40V
(d) 0.80V