Question

State the formula for the following:

Average power in LCR circuit

Answer 1

Average power consumed over one cycle in the case of a series LCR AC circuit,

P_av = e_rms  i_rms cos`phi`

∴ `P_(av) = e_(rms)  i_(rms) = e_(rms) (e_(rms)/Z) (R/Z)`

= `(R(e_(rms))^2)/Z^2 = (R(e_(rms))^2)/(R^2 + (X_L - X_C)^2)`

Particular cases:

1. `P_(av) = (e_(rms)^2)/R`
2. P_av = 0
3. P_av = 0