A rectangular wire loop of sides 8 cm and 2 cm with a small cut is moving out of a region of uniform magnetic field of magnitude 0.3 T directed normal to the loop. What is the voltage developed across the cut if the velocity of the loop is `1 cm " "s^(-1)` in a direction normal to the : (i) longer side? For how long does the induced voltage last?

Explanation

Given : `l=8xx10^(-2)m, b=8 xx10^(-2)m ,B=0.3 T,nu=10^(-2)ms^(-1)`
Let .e. be induced emf developed across the cut in the loop.
`e_i=Bl" "nu=0.3 xx8xx10^(-2)xx10^(-2)V=2.4xx10^(-4)V`
The induced emf will last for the time during which the breath of the loop moves of the field.
Hence `t_1=(b)/(nu)=(2xx10^(-2))/(10^(-2))=2s`