The Lorentz force on this charge is qvB in magnitude,
and its direction is towards Q All charges experience the same force, in
magnitude and direction, irrespective of their position in the rod PQ The work done in moving the charge from P to Q is,
W = qvBl
Since emf is the work done per unit charge,
W
q
ε =
    = Blv
This equation gives emf induced across the rod PQ and is identical
to Eq (6