The magnetic flux in a closed circuit of resistance `10Omega` varies with time according to equation , `phi=6t^(2)-5t+1`. What is the magnitude of the induced current at `t=0.25s`?

Options

A. 1.2 A
B. 0.8 A
C. 0.6 S
D. 0.2 S

Answer

D

Explanation

By using, `i=e/R = -1/R (dphi)/(dt)`
`i=-1/10 d/(dt) (6t^(2) -5t+1) = -1/20 (12 -5)`
`i=-1/10 (12 xx 0.25-5) = 0.2 A`