A conducting rod of mass m and length l is placed over a smooth horizontal surface. A uniform magnetic field B is…..

Q. A conducting rod of mass m and length l is placed over a smooth horizontal surface. A uniform magnetic field B is acting perpendicular to the rod. Charge q is suddenly passed through the rod and it acquires an initial velocity v on the surface, then q is equal to

(a)  2mv/Bl

(b) Bl/2mv

(c)    mv/Bl

(d) Blv/2m

Ans: (c)