In an a.c circuit, value of voltage and current change every instant. Therefore, power of an a.c. circuit at any instant is the product of instantaneous voltages `(E)` and instantaneous current `(I)`. The average power supplied to a pure resistance `R` over a complete cycle of a.c is `P = E_(upsilon). I_(upsilon)`. When circuit is inductive, average power/cycle `= E_(upsilon) I_(upsilon) cos phi`, where `phi` is the phase angle between alternating voltage an altenating current in the circuit.
In an a.c. circuit, `800 mH` inductor and a `60 mu F` capacitor are connected in series with `15 ohm` resistance. The a.c. supply to the circuit is `230 V, 50 Hz`
The electrial energy spent in running the circuit for one hour is

Options

A. `20.0.5 J`
B. `20.05 k w h`
C. `7.22 xx 10^(4) J`
D. Zero

Answer

C

Explanation

As energy spent = power `xx` time
`:.` energy spent ` = 20.05 xx 60 xx 60`
`= 7.22 xx 10^(4)` Joule