A coil of 50 turns is pulled in 0.02 s fron between the poles of a magnet, where its are: includes magnetic flux of `31 xx 10^(-6)` Wb to the place, where its area includes `1 xx 10^(-6)` Wb. The average emf is ____

Options

A. `7.5xx10^(-2)`V
B. `7.5xx10^(-3)` V
C. 0
D. `7.5xx10^(-4)` V

Answer

A

Explanation

`epsilon=-N(Deltaphi)/(Deltat)`
`=-N[(phi_2-phi_1)/(Deltat)]`
`=-50[(1xx10^(-6)-31xx10^(-6))/0.02]`
`=+(50xx30xx10^(-6))/(2xx10^(-2))`
`therefore epsilon=7.5xx10^(-2)` V