The total opposition to current. $$Z = \sqrt{R^2 + (X_L - X_C)^2}$$ (Where $X_L = 2\pi fL$ and $X_C = \frac{1}{2\pi fC}$).
Using these tests to find the parameters of the equivalent circuit and calculate efficiency.
: This includes alternators (EMF equations, distribution, and pitch factors) and induction motors (slip, torque, and rotating magnetic fields). Measurement of Power (10% weight)