EECE 290 Lecture Slides Problem Solving Complex Power 2, Spring 2019

EECE 290, Problem solving Session 4 For a capacitance, A. P>0, Q=0 B. P=0, Q>0 C. P=0, Q<0 D. P<0, Q=0 P>0, Q=0 P=0, Q>0 P=0, Q<0 P<0, Q=0 0% 0% 0% 0% 20 |S| = 50 kVA, P = 40 kW, |Q|= ? A. 10 kVAR B. 20 kVAR C. 30 kVAR D. 40 kVAR E. 50 kVAR 10 kVAR 20 kVAR 30 kVAR 40 kVAR 50 kVAR 0% 0% 0% 0% 0% 20 Over a 1 mF capacitance the rms voltage is 4 V with ω=100 rad/s, what is the value of Q? A. -0.4 VAR B. -1.6 VAR C. 1.6 VAR D. 0.4 VAR -0.4 VAR -1.6 VAR 1.6 VAR 0.4 VAR 0% 0% 0% 0% 20 A load absorbs 1-j kVA. In order to get pf=1, we must? A. Put a capacitance in series. B. Put a capacitance in parallel. C. Put an inductance in parallel or series D. Put a resistance in series. Put a capacitance in series. Put a capacitance in paral... Put an inductance in para... Put a resistance in series. 0% 0% 0% 0% 20 A current source of 0.1 Arms, a capacitance of –j4 Ω and an inductance of j2 Ω are connected in series, what is the value of S? A. j20 mVA B. -j20 mVA C. -j2 mVA D. j2 mVA j20 mVA -j20 mVA -j2 mVA j2 mVA 0% 0% 0% 0% 20 Zsrc=2+j2Ω, for maximum power transfer, ZL=? A. 2+j2Ω B. 2-j2Ω C. -2+j2Ω D. -2-j2Ω 20 Zsrc ZL IL VSRC – +∼ a b Zsrc=2+j2Ω, ZL has the value for maximum power transfer, how much power is transferred? 𝑉𝑉𝑠𝑠𝑠𝑠𝑠𝑠 is the amplitude. A. 𝑉𝑉𝑠𝑠𝑠𝑠𝑠𝑠 2/16 B. 𝑉𝑉𝑠𝑠𝑠𝑠𝑠𝑠 2/4 C. 𝑉𝑉𝑠𝑠𝑠𝑠𝑠𝑠 2/2 D. 2𝑉𝑉𝑠𝑠𝑠𝑠𝑠𝑠 2/ 2 $$ $$$$$$ 2 /16 $$ $$$$$$ 2 /4 $$ $$$$$$ 2 /2 2 $$ $$$$$$ 2 / 2 0% 0% 0% 0% 20 Zsrc ZL IL VSRC – +∼ a b