An emf of 0 . 08V is induced in a metal rod of length 10cm held...

The formula to calculate the motional emf induced in a moving conductor in a magnetic field is given by

$ε = Blv . . . \left(1\right)$

Substitute the values of the known parameters into equation (1) and solve to calculate the required velocity of the rod.

$\begin{cases}0 . 08V & = & 0 . 4T \times \left(10cm \times \dfrac{1m}{100cm}\right) \times v \\ & ⇒ & v = \dfrac{0 . 08V}{0 . 4T \times 10cm \times \dfrac{1m}{100cm}} \\ & = & 2m{s}^{- 1}\end{cases}$