An a.c source of frequency `1000 Hz` is connected to a coil of `(200)/(pi) mH` and negligible resistance. If effective current through the coil is `7.5 mA`, what is the voltage (in volt) across the coil ?

Answer

3

Explanation

Here, `v = 1000 Hz, L = (200)/(pi) = (0.2)/(pi) H`
`I_(upsilon) = 7.5 mA = 7.5 xx 10^(-3) A, E_(upsilon) = ?`
As resistance of coil is negilgible,
`:. E_(upsilon) = I_(upsilon) (X_(L)) = I_(upsilon) (2 pi v L)`
`= 7.5 xx 10^(-3) (2 pi xx 1000 xx (0.2)/(pi)) = 3 V`