The correct option is
B 16 N
Let induced emf is (e) = V B l
where V = velocity of conductor , B = magnetic field intensity , l = length of conductor.
Current is I.If resistance of loop is 2 R then circuit will be .
current I=eR1∥R2
=2e1=2VBl
Force Fm=ilB=2vB2l2=2×1×22×2Fm=16N