A straight conductig rod `PQ` is executing `SHM` in xy-plane from `x=-d` to `x=+d.` Its mean position is `x=0` and its length is along `y`-axis. There exists a uniform magnetic field B from `x=-d` to `x=0` pointing inward normal to the paper andfrom `x=0` to `x=+d` there exists another uniform magnetic field of same magnetic `B` but pointing outward normal to the plane of the paper. At the instant `t=0`, the rod is at `x=0` and moving to the right. The induced emf (epsilon) acorss the rod `PQ` `vs` time (`t`) graph will be

Options

A.
B.
C.
D.

Answer

B

Explanation

At mean position, velocity is maximum. Hene, motional emf `Bvl` is also maximum. `V` oscillates simple harmonically. Hence, motional emf willl simple harmonically . Further, polarity of induced emf will keep on changing.