The flux linked with a coil at any instant 't' is given by `phi = 10t^(2) - 50t +250`
The induced emf at `t = 3s` is

Options

A. `-10V`
B. 10V
C. 190V
D. `-190V`

Answer

A

Explanation

Here `phi = 10t^2 - 50t + 250`
The induced emf is
`epsi = - (dphi)/(dt) = - (d)/(dt) (10t^2 - 50t + 250) = - (20t - 50)`
At `t =3 s, epsi = -(20 xx 3 - 50) = -10V`