An electrical device draws 2kW power from AC mains (voltage 223V (rms) = 50,000 V). The current differs (lags) in phase by φ (tan φ = -3/4) as compared to voltage.
Find (i) R,
(ii) X_{c}-X_{l},
and (iii) I_{M}. Another device has twice the values for R, X_{C} and X_{L}. How are the answers affected?
An electrical device draws 2kW power from AC mains (voltage 223V (rms) = 50,000 V). The current differs (lags) in phase by φ (tan φ = -3/4) as compared to voltage.
Find (i) R,
(ii) X_{c}-X_{l},
and (iii) I_{M}. Another device has twice the values for R, X_{C} and X_{L}. How are the answers affected?

Impedance is given as Z = 25 ohms

635=25R^{2}/16

a) Resistance can be calculated as,

R=\sqrt 25\times 16=\sqrt 400=20 ohms

b) X_{c}-X_{l}=-3R/4=-15ohms

c) Main current will be I_{m}=12.6A