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1

In a capacitive circuit, the current delivered to a capacitor will rise to 63 percent of its maximum value after charging for a period of one time constant.
A)True
B)False
2

In an inductive circuit, the current decays to 37 percent of its initial value in a period of one time constant.
A)True
B)False
3

A capacitor with a breakdown voltage of 150 V would be safe to use in an ac circuit if the ac voltage were only 120 V
A)True
B)False
4

Capacitive reactance and inductive reactance increase with an increase in frequency of an alternating current.
A)True
B)False
5

The effective voltage V in a series ac circuit can be defined as the algebraic sum of VC, VL, and VR.
A)True
B)False
6

The power factor in an ac circuit is the ratio of its resistance to its impedance.
A)True
B)False
7

Under a condition of resonance in an ac circuit, the current will be in phase with the voltage.
A)True
B)False
8

Reactance, impedance, and resistance are all measured in the same physical unit (ohms).
A)True
B)False
9

In a circuit containing pure capacitance, the voltage leads the current by 90°.
A)True
B)False
10

A negative phase angle occurs when the current leads the voltage in an ac circuit.
A)True
B)False
11

The voltage of a circuit containing only inductive reactance
A)is in phase with the current
B)leads the current by 90°
C)lags the current by 90°
D)leads the current by less than 90°
12

An alternating voltage has a maximum value of 30 V. The effective value is approximately
A)15 V
B)21.2 V
C)30 V
D)42.9 V
13

As the capacitance in an ac circuit increases, the resonant frequency
A)increases
B)decreases
C)remains the same
D)approaches zero
14

The ratio of the pure resistance in an ac circuit to the impedance is known as the
A)power factor
B)phase angle
C)resonant frequency
D)net reactance
15

In a circuit containing pure capacitance, during a period of one time constant, the
A)charge decays to 63 percent of its initial value
B)charge increases to 37 percent of its initial value
C)current decays to 37 percent of its initial value
D)capacitor is completely charged
16

In an ac circuit containing a coil with an inductance of 0.3 H, the voltage is 120 V at 60 Hz. If we neglect resistance, the effective current in the coil is
A)0.27 A
B)0.53 A
C)1.06 A
D)2.12 A
17

A 50-Ω resistor, a 0.5-H inductor, and a 12- μF capacitor are connected in series with a 120-V, 60-Hz alternating current. The effective current is approximately
A)2 A
B)4 A
C)6 A
D)8 A
18

In Question 17, the power factor is
A)0.66
B)0.72
C)0.83
D)0.92
19

An 800-Ω resistor, a 0.6-H inductor, and a 4- μF capacitor are connected in series with a 220-V, 50-Hz source of alternating current. The phase angle is approximately
A)-31°
B)-37°
C)31°
D)37°
20

A circuit contains a 12-μF capacitor, a 40-Ω resistor, a switch, and a 20-V dc battery connected in series. After the switch is closed, the capacitor can be considered fully charged after
A)0.00048 s
B)0.0012 s
C)0.0024 s
D)0.0048 s
21

One effective ampere is that alternating current that will develop the same as of direct current.
22

In a(n) circuit, the current decays to 37 percent of its initial value in a period equal to one .
23

In a capacitive circuit, the leads the , and the phase angle is .
24

For an ac circuit containing capacitance, inductance, and resistance, the current will be a maximum when the frequency of the alternating voltage is equal to .
25

The power factor is equal to the of the circuit divided by the .
26

When the voltage and current reach maximum and minimum values at the same time, they are said to be .
27

A given inductor has an inductance of one if an emf of one is induced by a current changing at the rate of one .
28

In an inductive circuit, an increase in frequency of the applied voltage will the effective current.
29

At resonant frequency, an ac circuit containing resistance, inductance, and capacitance acts as if it contained only .
30

A household ac circuit has a 110-V, 60-Hz source of current. The actual voltage varies from to .







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