Electrical Engineering Questions -
Q1. Two ideal voltage sources designated as machines 1 and 2 are connected, as shown in the figure below.
Given E_{1} = 65∠0^{o}V, E_{2} = 65∠30^{o}V, Z = 3Ω. Determine if
Machine 1 is generating active power and |P_{1}| = _______ W
Machine 2 is generating active power and |P_{2}| = _______ W
Machine 1 is delivering reactive power and |Q_{1}| = _______ var
Machine 1 is receiving reactive power and |Q_{2}| = _______ var
Z is absorbing _______ W.
Q2. A three-phase 440-V line is supplying a three-phase 14-hp motor operating at full load, 80% efficient and 83% power factor lagging. Find the values of P and Q drawn from the line
P = _______ (kW)
Q = _______ (kW)
Q3. Find the line-to-line voltage at the bus, which supplies 440-V line at a three-phase 18-hp motor operating at full load, 86% efficient and 85% power factor lagging. The impedance of each of the three lines connecting the bus and the motor is 0.3 + 0.8jΩ.
|V_{line-to-line}| = _______ (V)
Note: this question is checked to one decimal place.
Q4. A three-phase load draws 23kva at a power factor of 0.8 lagging from a 220 - V line. The kVAR of the capacitor to make the combined power factor 0.85 lagging is ______ kvar help (numbers).
Before connecting the capacitor, |I| = ______ A
After connecting the capacitor, |I| = ______ A
Note: this question is checked to two decimal places.