Delmars Unit 20 Capacitance in AC Circuits

A 1 μF capacitor has 2,652 Ω of reactance at 60 Hz. What is the reactance value at 400 Hz? 639.79 Ω 568.72 Ω 397.88 Ω 768.33 Ω

397.88 Ω

Two capacitors, a 20 μF and a 30 μF, are connected in parallel to a 60 Hz source. What is the total capacitive reactance? 7.96 Ω 53.05 Ω 42.04 Ω 23.16 Ω

53.05 Ω

A 35 μF capacitor is connected to a 60-Hz, 120 V supply. What is the XC of the capacitor? 75.79 Ω 93.43 Ω 83.2 Ω 80.33 Ω

75.79 Ω

The quality of a capacitor is found by Q = _____. PF XC/R R/XC W/VARs

R/XC

The voltage rating of a capacitor _____. is a minimum working voltage can be exceeded as long as the time is under one hour is only a suggested maximum should never be exceeded

should never be exceeded

When the voltage and current have _____ polarities in a pure capacitive circuit, the capacitor is discharging and the energy is returned to the circuit. ​opposite ​the same

​opposite

What is the reactance of a 25 μF capacitor when the applied frequency is 400 Hz? 16.12 Ω 11.59 Ω 10.61 Ω 15.92 Ω

15.92 Ω

In a circuit containing a capacitor, the impressed voltage is _____ with the applied voltage. 180° out of phase 90° out of phase 270° out of phase in phase

180° out of phase

Two capacitors, a 20 μF and a 30 μF, are connected in series to a 60 Hz source. What is the total capacitive reactance? 333.16 Ω 221.04 Ω 253.05 Ω 117.96 Ω

221.04 Ω

Two capacitors, a 20 μF and a 30 μF, are connected in series to a 400 Hz source. What is the total capacitive reactance? 33.16 Ω 53.05 Ω 7.96 Ω 42.04 Ω

33.16 Ω

Three capacitors, a 12 μF, a 20 μF, and a 30 μF, are connected in parallel to a 60 Hz source. What is the total XC? 42.78 Ω 566.32 Ω 442.09 Ω 6.42 Ω

42.78 Ω

Three capacitors, a 12 μF, a 20 μF, and a 30 μF, are connected in series to a 60 Hz source. What is the total XC? 566.32 Ω 442.09 Ω 226.42 Ω 342.78 Ω

442.09 Ω

What is the reactance of a 10 pF capacitor when the applied frequency is 30 Hz? 530.52 Ω 200.36 Ω 612.83 Ω 325.76 Ω

530.52 Ω

Three capacitors, a 12 μF, a 20 μF, and a 30 μF, are connected in parallel to a 400 Hz source. What is the total XC? 6.42 Ω 44.09 Ω 42.78 Ω 56.32 Ω

6.42 Ω

Three capacitors, a 12 μF, a 20 μF, and a 30 μF, are connected in series to a 400 Hz source. What is the total XC? 42.78 Ω 36.42 Ω 52.09 Ω 66.32 Ω

66.32 Ω

Two capacitors, a 20 μF and a 30 μF, are connected in parallel to a 400 Hz source. What is the total capacitive reactance? 42.04 Ω 33.16 Ω 7.96 Ω 53.05 Ω

7.96 Ω

A capacitor is connected to a 240 V supply. An ammeter indicates 3 A. What is the capacitive reactance of the capacitor? 71 Ω 23 Ω 80 Ω 30 Ω

80 Ω

The power in a capacitor is reactive power. What is the unit for reactive power? W P VA VAR

VAR

Countervoltage presented by a capacitor is called _____. inductive reactance capacitive reactance capacitance inductance

capacitive reactance

When a capacitor is connected to a(n) _____ circuit, current appears to flow through the capacitor. AC DC

AC

The capacitive reactance of a capacitor is _____ proportional to frequency. directly inversely

inversely

In a pure capacitive circuit, the current _____ the applied voltage by _____. lags; 180° lags; 90° leads; 180° leads; 90°

leads; 90°

What is the unit for capacitive reactance? coulomb farad henry ohm

ohm