Deck 9: Branch, Loop, and Node Analyses

Question 1

What is one time constant of a capacitor in series with a resistor?

A)1.03 ms
B)103 ms
C)0.103 ms
D)10.3 ms

Answer 1

103 ms

Question 2

If the dc working voltage of a capacitor is 100 V, the dielectric must withstand ________.

A)85 VRMS
B)75 VRMS
C)100 VDC
D)220 VPP

Answer 2

100 VDC

Question 3

Capacitance is the ability to store voltage.

Answer 3

False

Question 4

When two capacitors are connected in series across a dc source, the smallest capacitor drops the
largest voltage.

Question 5

If a and capacitor are connected in parallel across a 20 V source, the total capacitance equals and each capacitor drops

A)
B)
C)
D)

Question 6

The voltage rating of a capacitor indicates the voltage it will charge up to.

Question 7

What is the capacitance of a capacitor that drops 50 V and stores 0.500 of charge?

A)
B)
C)
D)

Question 8

If the distance between the plates of a capacitor increases, the capacitance decreases.

Question 9

A capacitor can fully charge in one time constant.

Question 10

When two capacitors are connected in parallel across a dc source, the smaller capacitor drops the
larger voltage.

Question 11

Efficient filtering is directly related to RC time constant.

Question 12

Leakage through a capacitor is undesirable.

Question 13

To find the total capacitance of two capacitors in parallel, you must combine them using a similar
procedure as resistors in parallel.

Question 14

If a and capacitor are connected in series across a 25 V source, the voltage drop across the largest capacitor equals ________.

A)10.2 V
B)11.8 V
C)17.5 V
D)4.51 V

Question 15

Electrolytic capacitors are ideal for alternating current applications.

Question 16

If the plate area of a capacitor decreases, the capacitance decreases.

Question 17

A capacitor will fully charge in about five time constants.

Question 18

A capacitor blocks dc and passes ac.

Question 19

How much charge is stored in a capacitor that drops 22 V?

A)
B)
C)
D)

Question 20

Capacitance is a capacitorʹs ability to store resistance.

Question 21

How much charge is stored in a capacitor that drops 18 V?

A)
B)
C)
D)

Question 22

What is the minimum dc working voltage rating for a capacitor that must drop 120

A)84.8 V
B)120 V
C)170 V
D)339 V

Question 23

If a capacitor is connected to a 15 V 400 Hz source, its current equals ________.

A)55 mA
B)829 mA
C)18.1 mA
D)1.81 A

Question 24

If a capacitor and a resistor are connected in series across 25 V , approximately how much voltage will the resistor drop after charging for just one time constant?

A)23.8 V
B)21.6 V
C)15.8 V
D)9.20 V

Question 25

If a capacitor are connected in series across a 25 V source, the total capacitance equals and each capacitor drops

A)
B)
C)
D)

Question 26

If a capacitor and a resistor are connected in series across 30 , how much voltage will the capacitor drop after charging for just one time constant?

A)25.9 V
B)19.0 V
C)29.4 V
D)28.5 V

Question 27

How long will it take to completely charge a capacitor through a 1 resistor?

A)0.029 s
B)0.047 s
C)0.235 s
D)0.47 s

Question 28

If the frequency applied to a capacitor increases, the capacitive reactance ________.

A)decreases
B)remains the same
C)varies up and down
D)increases

Question 29

If an uncharged capacitor, a resistor, a switch and a 12 V battery are connected in series, at approximately what time will the capacitor reach full charge?

A)12 × R × C
B)R × C
C)5 × R × C
D)The time cannot be predicted.

Question 30

If a capacitor operates at 10 kHz, equals ________.

A)
B)
C)
D)

Question 31

If four capacitors are connected in parallel, equals ________.

A)
B)
C)
D)

Question 32

If an uncharged capacitor, a resistor, a switch and a 12 V battery are connected in series, what is the voltage across the capacitor after it is fully charged?

A)12 V
B)-6 V
C)6 V
D)24 V

Question 33

If a capacitor are connected in series, is less than ________.

A)
B)
C)
D)

Question 34

If an uncharged capacitor, a resistor, a switch and a 12 V battery are connected in series, what is the voltage across the capacitor at the instant the switch is closed?

A)24 V
B)0 V
C)6 V
D)12 V

Question 35

How long will it take a capacitor to fully charge through a resistor?

A)235 ms
B)2.35 s
C)0.235 ms
D)23.5 ms

Question 36

What is the capacitance that stores of charge and drops 25 V?

A)
B)
C)
D)

Question 37

If a capacitor are connected in series across a 75 V source, the voltage drop across the smallest capacitor equals ________.

A)50 V
B)100 V
C)37.5 V
D)18.8 V

Question 38

If a capacitor and a resistor are connected in series across 20 , approximately how much voltage will the capacitor drop after charging for just one time constant?

A)12.6 V
B)11.0 V
C)12.1 V
D)17 V

Question 39

A capacitor that transfers an ac signal from one stage to another is called a ________ capacitor.

A)filter
B)coupling
C)transfer
D)bypass

Question 40

At what frequency is a capacitor operating if its reactance is

A)107 kHz
B)1.01 kHz
C)10.1 kHz
D)1010 Hz

Question 41

If a capacitor are connected in parallel across a 15 V source, the total capacitance equals and the capacitor drops

A)
B)
C)
D)

Question 42

A common use for electrolytic capacitors found in power supplies is ________.

A)decoupling
B)filtering
C)passing AC
D)blocking DC

Question 43

When connecting a large electrolytic capacitor to a circuit with a source, place the negative end of the capacitor ________.

A)towards the negative side of the source
B)towards the positive side of the source
C)in either position; the polarity is not important

Question 44

A test instrument designed to be used for the testing of capacitors is the ________.

A)oscilloscope
B)LCR Meter
C)digital multimeter
D)analog multimeter

Question 45

What is one time constant of a capacitor in series with a resistor?

A)5.64 s
B)0.564 ms
C)54.6 s
D)564 ms

Question 46

The time constant for a capacitor for each time period is:

A)63% of the increase in value.
B)a constant factor.
C)37% of the decrease in value.
D)all of these.

Question 47

How long will it take for a capacitor to completely charge through a resistor?

A)5.17 s
B)8.272 s
C)1.034 s
D)2.068 s

Question 48

In a capacitive AC circuit, the phase relationship between the voltage and the current is such that the:

A)current is 180 degrees out of phase with voltage.
B)current is leading the voltage.
C)voltage is leading the current.
D)voltage is 360 degrees out of phase with current.

Question 49

If a capacitor operates at 220 kHz, XC equals ________.

A)
B)
C)
D)

Question 50

Reactive power in a capacitor is defined as the rate at which a capacitor stores or returns energy and is measured in:

A)watts reactive.
B)volt-ampere reactive.
C)current per time constant.
D)volts per time constant.

Question 51

What is in Figure?

A)
B)
C)
D)

Question 52

When capacitors are connected in series, their total capacitance act like:

A)resistance connected in series-parallel.
B)resistance connected in parallel.
C)resistance connected in series.
D)all of these.

Question 53

Electrolytic capacitors differ from many other capacitors in construction in that they are:

A)polarized.
B)larger.
C)smaller.
D)sensitized.

Question 54

How much voltage is dropped across a capacitor after 3.33 seconds if it is charged by a 50 V source through a resistor?

A)49 V
B)31.8 V
C)43.3 V
D)47.5 V

Question 55

How long will it take for a capacitor to completely discharge through a resistor?

A)0.103 s
B)0.827 s
C)0.517 s
D)0.207 s

Question 56

When capacitors are connected in parallel, their total capacitance act like:

A)resistance connected in parallel.
B)resistance connected in series-parallel.
C)resistance connected in series.
D)all of these.

Question 57

Electrolytic capacitors must be connected into a circuit such that:

A)reversal of polarity does not happen.
B)positive lead to positive voltage; negative lead to negative voltage.
C)voltage rating marked is not exceeded.
D)all of these.

Question 58

At what frequency is a capacitor operating if its reactance is

A)3.54 MHz
B)3.54 kHz
C)354 kHz
D)35.4 kHz

Question 59

If a capacitor is connected to a 20 V, 400 Hz source, the current is ________.

A)0.851 A
B)2.36 A
C)8.51 A
D)425 A

Question 60

The time constant of a capacitor is:

A)the time required to charge to 63% or discharge to 37%.
B)directly proportional to the resistance in the circuit.
C)directly proportional to the capacitance in the circuit.
D)all of these.

Question 61

A commonplace use for capacitors in electronics is to:

A)block AC voltages.
B)pass DC voltages only.
C)pass both AC and DC voltages.
D)block DC voltages.

Question 62

The removal of high frequency transient voltages with a capacitor is called:

A)ac blocking.
B)decoupling.
C)coupling.
D)bypassing.

Question 63

A 65 Vrms signal is applied to a 10 F capacitor. What is the total peak current?

A)6.5 kA
B)6.5 A
C)153 mA
D)not enough information

Question 64

With three capacitors in series, the current lags the voltage by:

A)30 degrees.
B)90 degrees.
C)45 degrees.
D)none of the above.

Question 65

Upon checking the voltage output of a power supply with an oscilloscope, you notice an unusually large amount of ripple. What could possibly be the problem?

A)shorted filter capacitor
B)shorted load
C)open filter capacitor
D)either B or C

Question 66

What is the small amount of power lost in a capacitive circuit due to the internal resistance of the capacitors?

A)instantaneous power
B)ideal power
C)reactive power
D)true power