6) When the frequency of an a.c. circuit containing resistance and capacitance is decreased, thecurrent(a) decreases(b) increases(c) stays the same7) In a series a.c. circuit the voltage across a pure inductance is 12 V and the voltage across a pureresistance is 5 V. The supply voltage is(a) 13 V(b) 17 V(c) 7 V(d) 2.4 V8) The impedance of a coil, which has a resistance of X ohms and an inductance of Y henrys,connected across a supply of frequency K Hz, is(a) 2π Κ Υ (b) X + Y(c) √x² + y²(d) √X² + (2nKY)²9) When a capacitor is connected to an a.c. supply the current(a) leads the voltage by 180°(c) leads the voltage by 1/2 rad(b) is in phase with the voltage(d) lags the voltage by 90°10) In an R-L-C series a.c. circuit a current of 5 A flows when the supply voltage is 100 V. Thephase angle between current and voltage is 60° lagging. Which of the following statements isfalse?(a) The circuit is effectively inductive(c) The equivalent circuit reactance is 25 2(b) The apparent power is 500 VA(d) The true power is 250 W11) An a.c. supply is 70.7 V, 50 Hz . Which of the following statements is false?(a) The periodic time is 20 ms.(b) The peak value of the voltage is 70.7 V(c) The r.m.s. value of the voltage is 70.7 V(d) The peak value of the voltage is 100 V12) When the frequency of an a.c. circuit containing resistance and capacitance is increased theimpedance(a) increases(b) decreases(c) stays the same

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6) When the frequency of an a.c. circuit containing resistance and capacitance is decreased, the current (a) decreases (b) increases (c) stays the same 7) In a series a.c. circuit the voltage across a pure inductance is 12 V and the voltage across a pure resistance is 5 V. The supply voltage is (a) 13 V (b) 17 V (c) 7 V (d) 2.4 V 8) The impedance of a coil, which has a resistance of X ohms and an inductance of Y henrys, connected across a supply of frequency K Hz, is (a) 2π Κ Υ (b) X + Y (c) √x² + y² (d) √X² + (2nKY)²

6) When the frequency of an a.c. circuit containing resistance and capacitance is decreased, the current (a) decreases (b) increases (c) stays the same 7) In a series a.c. circuit the voltage across a pure inductance is 12 V and the voltage across a pure resistance is 5 V. The supply voltage is (a) 13 V (b) 17 V (c) 7 V (d) 2.4 V 8) The impedance of a coil, which has a resistance of X ohms and an inductance of Y henrys, connected across a supply of frequency K Hz, is (a) 2π Κ Υ (b) X + Y (c) √x² + y² (d) √X² + (2nKY)²

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter20: Capacitance In Ac Circuits

Section: Chapter Questions

Problem 2PA: You are working in an industrial plant. You have been instructed to double the capacitance connected...

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