The current is a solenoid of 240 turns, having a length of 12 cm and a radius of 2 cm, changes at a rate of `0.8 A s^(-)`. Find the emf indcued in it.

Explanation

Here, `N = 240, l = 12 cm = 12 xx 10^(2) m`,
`r = 2 cm = 2 xx 10^(-2) m, A = pi r^(2)`
`dI//dt = 0.8 As^(-1), e = ?`
`L = (mu_(0) N^(2) A)/(l) = (4 pi xx 10^(-7) (240)^(2) xx pi (0.02)^(2))/(0.12)`
`|e| = (L dI)/(dt) = (4 pi xx 10^(-7) (240)^(2) xx 3.14 xx 4 xx 10^(-4) xx 0.8)/(0.12)`
`= 6 xx 10^(-4) V`