Deck 15: RC Circuits

Question 1

The output of an RC integrator is the capacitorʹs voltage drop.

Answer 1

True

Question 2

What is VC at the end of the input pulse to an RC integrator if the input pulse is 15 V and the pulse width equals one time constant?

A)9.48 V
B)13.0 V
C)14.25 V
D)14.7 V

Answer 2

9.48 V

Question 3

In an RC integrating circuit, the output is taken across the capacitor.

Answer 3

True

Question 4

An open inductor in an RL differentiator will cause the output to resemble the input.

Question 5

When the input pulse width to an RC integrator is much less than the output approaches the
shape of the input.

Question 6

An RC integrating circuit is a basic high-pass filter with a pulse applied to it.

Question 7

The output of an RC differentiating circuit is taken across the resistor.

Question 8

The output from an RL integrator can look exactly the same as the output from an RC integrator.

Question 9

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

A)0.264 s
B)132 s
C)2.64 s
D)13.2 s

Question 10

An RL integrator is a basic RL low-pass filter with a pulse applied to it.

Question 11

LC and RC integrators, with respect to input and output, perform exactly the same.

Question 12

In an RC integrator, as the time constant gets longer, the maximum capacitor voltage gets smaller.

Question 13

In an RL integrating circuit, the output is taken across the inductor.

Question 14

The output of an RC differentiator with an open capacitor will look like the input.

Question 15

Since voltage is constant during the peak of a pulse input, the output of an LC integrator is
constant during this time as well.

Question 16

It takes a capacitor 5 time constants to nearly reach full charge.

Question 17

What is one time constant in an integrating circuit if a resistor is in series with a capacitor?

A)0.47 ms
B)4.7 s
C)
D)

Question 18

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

A)0.47 ms
B)2.35 ms
C)5 s
D)0.18 ms

Question 19

What is one time constant in an integrating circuit if a resistor is in series with a capacitor?

A)0.047 ms
B)0.47 ms
C)0.47 s
D)

Question 20

The output of a differentiator circuit will reach the same maximum and minimum levels as the
input as long as the time constant of the circuit is less than the width of the input pulse.

Question 21

If the input pulse to an RC differentiator is very short compared to the circuitʹs time constant, the differentiatorʹs output is ________.

A)a dc value of about half the peak input voltage
B)a square wave very similar to the input voltage
C)zero volts
D)a dc voltage equal to the peak input voltage

Question 22

The output from an RL differentiator is taken across the ________.

A)resistor
B)resistor and inductor
C)source
D)inductor

Question 23

The output from an RC integrator resembles the input if ________.

A) is less than the pulse width
B) is much larger that the pulse width
C) is much less than the pulse width
D) is equal to the pulse width

Question 24

To charge a 1 capacitor in 15 seconds, use a ________ resistor.

A)
B)
C)
D)

Question 25

The capacitor of an RC integrator charges to ________ if the input is a 10 V pulse with a pulse width equal to six time constants.

A)6.3 V
B)3.7 V
C)10 V
D)5 V

Question 26

The output from an RC differentiator resembles the input if ________.

A) is less than the pulse width
B) is equal to the pulse width
C) is much less than the pulse width
D) is much larger that the pulse width

Question 27

What is VC at the end of the input pulse to an RC integrator if the input pulse is 12 V and the pulse width equals one time constant?

A)7.59 V
B)4.41 V
C)12 V
D)0 V

Question 28

How does the RC differentiator output look when is much less than the pulse width?

A)square waves
B)positive spikes
C)negative spikes
D)positive and negative spikes

Question 29

What is the output voltage at the end of the input pulse to an RL integrator if the resistance is 1 kΩ, the inductor is 1 H and the input is a 22 V, 2 ms pulse?

A)20.9 V
B)21.6 V
C)13.9 V
D)19.0 V

Question 30

What is VC at the end of the input pulse to an RC integrator if the resistance is the capacitance is 0.05 μF and the input is a 12 V, 2.2 ms pulse?

A)4.42 V
B)7.58 V
C)10.4 V
D)12 V

Question 31

RC and RL integrators provide the same output when the inputs are ________.

A)the same
B)the outputs are never the same
C)different

Question 32

What is one time constant in an integrating circuit if a resistor is in series with a capacitor?

A)0.0235 ms
B)2.35 ms
C)0.00235 ms
D)235 ms

Question 33

What is output voltage at the end of the input pulse to an RC integrator if the resistance is the capacitance is 100 μF and the input is a 50 V, 10 s pulse?

A)31.6 V
B)47.5 V
C)43.25 V
D)50 V

Question 34

What is output voltage at the end of the input pulse to an RL integrator if the resistance is the inductor is 2 H and the input is a 12 V, 0.0909 ms pulse?

A)11.8 V
B)10.4 V
C)7.59 V
D)11.4 V

Question 35

What is VC at the end of the input pulse to an RC integrator if the resistance is the capacitance is and the input is a 15 V, 4.7 ms pulse?

A)13.0 V
B)14.7 V
C)14.3 V
D)9.48 V

Question 36

What is the output voltage from an RL integrator that uses a 10 mH inductor, a resistor and a 16 V, 1 ms input pulse?

A)16.3 V
B)13.8 V
C)10.1 V
D)15.2 V

Question 37

If RC and RL differentiators with equal time constants receive the same pulse, ________.

A)one outputs an increasing exponential while the other outputs a decreasing exponential
B)the RL has the most narrow spikes on the output
C)the RC has the widest output pulse
D)you canʹt tell the difference by observing the output wave forms

Question 38

The capacitor of an RC integrator charges to ________ if the input is a 10 V pulse with a pulse width equal to one time constant.

A)6.3 V
B)5 V
C)10 V
D)3.7 VC

Question 39

What is the output voltage at the end of the input pulse to an RL integrator if the resistance is 1.2 k Ω, the inductor is 200 mH and the input is a 5 V, 1.2 ms pulse?

A)4.532 V
B)5 V
C)4.75 V
D)3.16 V

Question 40

If an RC integrator uses a capacitor, a 1 resistor and a square wave input with a frequency of 200 kHz, its approximate output is ________.

A)a square wave with a frequency of 100 kHz
B)a near dc voltage of about half the peak square wave voltage
C)0 V
D)a square wave with a frequency of 200 kHz

Question 41

If the input pulse to an RC differentiator is very short compared to the circuitʹs time constant, then the differentiatorʹs output is ________.

A)zero volts
B)a square wave very similar to the input voltage
C)a dc voltage equal to the peak input voltage
D)a dc value of about half the peak input voltage

Question 42

RC and RL integrators produce an output voltage that equals the:

A)mathematical difference.
B)mathematical product.
C)mathematical average.
D)mathematical sum.

Question 43

If a square wave input produces 0 V output from an RC integrator, ________.

A)the resistor is shorted
B)the capacitor is leaky
C)the capacitor is open
D)the resistor is open

Question 44

What is the output voltage at the end of the input pulse from an RL integrator that uses a 200 mH inductor, a resistor and a 12 V, 9.09 μs input pulse?

A)10.38 V
B)7.59 V
C)11.76 V
D)11.4 V

Question 45

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

A)0.47 ms
B)23.5 ms
C)2.35 s
D)0.18 ms

Question 46

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

A)4.58 s
B)5.72 s
C)2.29 s
D)1.14 s

Question 47

Pulse width (tW) is defined as:

A)the time interval between identical points on the pulse.
B)the time interval between changes in the pulse.
C)the time interval between opposite points on the pulse.
D)all of these.

Question 48

What is the output voltage at the end of the input pulse from an RL integrator that uses a 2 H inductor, a resistor and a 32 V, 0.4 ms input pulse?

A)13.9 V
B)27.7 V
C)19.0 V
D)21.6 V

Question 49

To completely charge a capacitor in 15 seconds, use a ________ resistor.

A)
B)
C)
D)

Question 50

In RC and RL integrators and differentiators, transient time is equal to the:

A)pulse width.
B)time constant.
C)time constant times five.
D)pulse width times five.

Question 51

How does the RC differentiator output look when is much longer than the pulse width?

A)positive and negative spikes
B)positive spikes
C)square waves
D)negative spikes

Question 52

What is the output voltage at the end of the input pulse from an RL integrator that uses a 400 mH inductor, a resistor and a 5 V, 1.2 ms input pulse?

A)4.75 V
B)5 V
C)4.532 V
D)3.16 V

Question 53

RC integrators can be used in timing circuits to set a specified time delay if the output is coupled to:

A)a voltage threshold sensitive circuit.
B)a power threshold sensitive circuit.
C)a voltage generating circuit.
D)a current sensitive circuit.

Question 54

What is the time constant in an RC integrating circuit if a resistor is in series with a capacitor?

A)22 ms
B)2.2 s
C)2.2 ms
D)0.22 ms

Question 55

What is VC at the end of the input pulse to an RC integrator if the resistance is the capacitance is 47 and the input is a 15 V, 470 ms pulse?

A)9.48 V
B)14.3 V
C)13 V
D)14.7 V

Question 56

RC integrators can be used to convert a repetitive pulse waveform to a constant dc voltage equal to the average voltage of the waveform if:

A)τ is very large compared to tW.
B)τ is equal to tW.
C)τ is very small compared to tW.
D)τ is five times tW.

Question 57

The capacitor of an RC integrator charges to ________ if the input is a 30 V pulse with a pulse width equal to one time constant.

A)26.0 V
B)29.4 V
C)19.0 V
D)28.5 V

Question 58

The output of an RL integrator is taken across the ________.

A)resistor
B)inductor
C)resistor and inductor
D)source

Question 59

What is the output voltage at the end of the input pulse to an RC integrator if the resistance is 12 k Ω, the capacitance is and the input is a 50 V, 1 s pulse?

A)50 V
B)43.25 V
C)31.6 V
D)47.5 V

Question 60

What is the time constant in an RC integrating circuit if a resistor is in series with a capacitor?

A)0.044 μs
B)0.44 s
C)0.044 ms
D)0.44 ms

Question 61

RC and RL differentiators produce an output voltage that closely approximates the:

A)mathematical average.
B)mathematical difference.
C)mathematical rate of change process.
D)mathematical sum.

Question 62

Polarity of the output of an RL differentiator is determined by:

A)the time constant of the RL circuit.
B)the polarity of the incoming pulse.
C)the placement of the inductor.
D)an external clipping circuit.

Question 63

A given circuit using an RC integrator to turn on after 20 seconds now takes has been taking much longer to turn on. Now it entirely fails to turn on. What is the problem?

A)The resistor has opened.
B)The capacitor has decreased in value.
C)The capacitor has increased in value.
D)The resistor has decreased in value.

Question 64

A pulse-waveform to DC convertor makes use of an integrator:

A)with a time constant shorter than the width of the input pulse.
B)with a time constant much wider than the width of the input pulse.
C)with an extremely large time constant.
D)either B or C

Question 65

A timing circuit makes use of which of the following?

A)RC integrator
B)RC Differentiator
C)RL differentiator
D)either A or C

Question 66

A given circuit using an RC integrator to turn on after 20 seconds now takes now takes much longer to turn on. What is the most probable cause?

A)The resistor has decreased in value.
B)The capacitor has decreased in value.
C)The capacitor has increased in value.
D)The resistor has opened.