Question

How fast should a wire 20 cm long be moved through a 0.05-T magnetic field for an emf of 1 V to appear across its ends? 

Answer 1

$E=Blvsin\theta$

$\theta=90°\\l=0.20m \\B=0.05T\\E=1V$

Put value

$v=\frac{E}{Blsin\theta}$

$v=\frac{1}{0.05\times0.2\times sin90°}$

$v=\frac{1000}{10}=100m/sec$