A vertical rod of length ‘l’ in moved with constant velocity ‘V’ towards east.  The vertical component of the earth’s magnetic field is B and the angle of dip is '$\theta$’ The induced emf in the rod is 

$$\begin{gathered} \mathrm{As} \mathrm{the} \mathrm{rod} \mathrm{is} \mathrm{vertical} \mathrm{and} \mathrm{moving} \mathrm{horizontally} \mathrm{towards} \mathrm{east} \\ \mathrm{horizontal} \mathrm{component} \mathrm{of} \mathrm{earth} \mathrm{magnetic} \mathrm{feild} \mathrm{need} \mathrm{to} \mathrm{be} \mathrm{taken} \end{gathered}$$

$\mathrm{If} \mathrm{vertical} \mathrm{component} \mathrm{is} \mathrm{B} \mathrm{horizontal} \mathrm{component} \mathrm{will} \mathrm{be} \mathrm{B} \mathrm{cot\theta }$

$\mathrm{Induced} \mathrm{emf} \mathrm{Blcot\theta V}$