Question 1

The range of low frequencies passed by a low-pass filter within a specified limit is called the stopband.

Accepted Answer

A) True 
 B)False  False

Question 2

-In a low-pass RC filter, having a cutoff frequency of 2 kHz, C = 80nF. Determine R.

Accepted Answer

A)  98.0 Ω 
B)  44.7 Ω 
C)  995 Ω 
D)  22.7 Ω 
A)  98.0 Ω 
B)  44.7 Ω 
C)  995 Ω 
D)  22.7 Ω C

Question 3

-A high-pass RC filter can be changed to a low-pass RC filter by _ .

Accepted Answer

A)  adding another capacitor 
B)  reversing the position of the resistor and capacitor 
C)  adding another resistor 
D)  adding both another resistor and capacitor 
A)  adding another capacitor 
B)  reversing the position of the resistor and capacitor 
C)  adding another resistor 
D)  adding both another resistor and capacitor B

Question 4

The output voltage of the circuit in Figure 18-5, at the cut-off critical) frequency is:

Accepted Answer

A)  7.07 V 
B)  0.707 V 
C)  4.9 V 
D)  1.59 V 
A)  7.07 V 
B)  0.707 V 
C)  4.9 V 
D)  1.59 V

Question 5

What is the output voltage, in Figure 18-3 at a frequency of 1.0 kHz?

Accepted Answer

A)  0.269 V 
B)  4.90 V 
C)  1.76 V 
D)  3.45 V 
A)  0.269 V 
B)  4.90 V 
C)  1.76 V 
D)  3.45 V

Question 6

The critical frequency of the circuit in Figure 18-5 is:

Accepted Answer

A)  1.59 kHz 
B)  135 Hz 
C)  159 Hz 
D)  60 Hz 
A)  1.59 kHz 
B)  135 Hz 
C)  159 Hz 
D)  60 Hz

Question 7

Figure 18-7
-Identify the filter circuit in Figure 18-7 above.

Accepted Answer

A)  Band Stop 
B)  Low Pass 
C)  High Pass 
D)  Band Pass 
A)  Band Stop 
B)  Low Pass 
C)  High Pass 
D)  Band Pass

Question 8

Which of the following equations is correct for calculating the critical or cut-off frequency for the circuit in Figure 18-5?

Accepted Answer

A)  Fc = 1/2n LR) 
B)  Fc = 1/[2n L/R)] 
C)  Fc = 1/[2n LR)] 
D)  Fc = 2nL/R) 
A)  Fc = 1/2n LR) 
B)  Fc = 1/[2n L/R)] 
C)  Fc = 1/[2n LR)] 
D)  Fc = 2nL/R)

Question 9

Frequency response is a graph of voltage gain versus frequency.

Accepted Answer

A) True 
 B)False

Question 10

The circuit in Figure 18-1 has a critical frequency of:

Accepted Answer

A)  3.18 kHz 
B)  31.8 kHz 
C)  3.18 MHz 
D)  318 kHz 
A)  3.18 kHz 
B)  31.8 kHz 
C)  3.18 MHz 
D)  318 kHz

Question 11

The output voltage, in Figure 18-3 is how many dB down from the input voltage, at the critical frequency?

Accepted Answer

A)  -20 dB 
B)  -0.707 dB 
C)  0 dB 
D)  -3 dB 
A)  -20 dB 
B)  -0.707 dB 
C)  0 dB 
D)  -3 dB

Question 12

Figure 18-3
   Figure 18-4
-Which of the two response curves in Figure 18-4 A or B) represents the response of the circuit in Figure 18-3?

Accepted Answer

A)  Curve A 
B)  Curve B 
A)  Curve A 
B)  Curve B

Question 13

The is defined as the difference between the high and low cut-off frequencies.

Accepted Answer

A)  Q frequency range 
B)  bandwidth 
C)  roll-off 
D)  filter width 
A)  Q frequency range 
B)  bandwidth 
C)  roll-off 
D)  filter width

Question 14

The output voltage, in Figure 18-1 is how many dB down from the input voltage, at the critical frequency?

Accepted Answer

A)  -0.707 dB 
B)  -20 dB 
C)  -3 dB 
D)  0 dB 
A)  -0.707 dB 
B)  -20 dB 
C)  -3 dB 
D)  0 dB

Question 15

Figure 18-3
-The filter in Figure 18-3 has a Roll-off of:

Accepted Answer

A)  -3 dB per decade 
B)  -20 dB per decade 
C)  -40 dB per decade 
D)  -6 dB per decade 
A)  -3 dB per decade 
B)  -20 dB per decade 
C)  -40 dB per decade 
D)  -6 dB per decade

Question 16

The term "attenuation" refers to a:

Accepted Answer

A)  phase shift 
B)  loss or reduction of signal strength 
C)  signal gain 
D)  unity gain 
A)  phase shift 
B)  loss or reduction of signal strength 
C)  signal gain 
D)  unity gain

Question 17

Figure 18-3
-The circuit in Figure 18-3 is:

Accepted Answer

A)  a high-pass filter 
B)  a band-stop filter 
C)  a low-pass filter 
D)  a band-pass filter 
A)  a high-pass filter 
B)  a band-stop filter 
C)  a low-pass filter 
D)  a band-pass filter

Question 18

The filter in Figure 18-1 has a Roll-off of:

Accepted Answer

A)  -40 dB per decade 
B)  -3 dB per decade 
C)  -20 dB per decade 
D)  -6 dB per decade 
A)  -40 dB per decade 
B)  -3 dB per decade 
C)  -20 dB per decade 
D)  -6 dB per decade

Question 19

Figure 18-3
-The capacitive reactance in Figure 18-3 is equal to the resistance at the critical frequency.

Accepted Answer

A) True 
 B)False

Question 20

Figure 18-9
-Identify the filter circuit in Figure 18-9 above.

Accepted Answer

A)  High Pass 
B)  Band Pass 
C)  Band Stop 
D)  Low Pass 
A)  High Pass 
B)  Band Pass 
C)  Band Stop 
D)  Low Pass

Exam 18: Passive Filters

The range of low frequencies passed by a low-pass filter within a specified limit is called the stopband.

-In a low-pass RC filter, having a cutoff frequency of 2 kHz, C = 80nF. Determine R.

-A high-pass RC filter can be changed to a low-pass RC filter by _ .

The output voltage of the circuit in Figure 18-5, at the cut-off critical) frequency is:

What is the output voltage, in Figure 18-3 at a frequency of 1.0 kHz?

The critical frequency of the circuit in Figure 18-5 is:

Figure 18-7 -Identify the filter circuit in Figure 18-7 above.

Which of the following equations is correct for calculating the critical or cut-off frequency for the circuit in Figure 18-5?

Frequency response is a graph of voltage gain versus frequency.

The circuit in Figure 18-1 has a critical frequency of:

The output voltage, in Figure 18-3 is how many dB down from the input voltage, at the critical frequency?

Figure 18-3 Figure 18-4 -Which of the two response curves in Figure 18-4 A or B) represents the response of the circuit in Figure 18-3?

The is defined as the difference between the high and low cut-off frequencies.

The output voltage, in Figure 18-1 is how many dB down from the input voltage, at the critical frequency?

Figure 18-3 -The filter in Figure 18-3 has a Roll-off of:

The term "attenuation" refers to a:

Figure 18-3 -The circuit in Figure 18-3 is:

The filter in Figure 18-1 has a Roll-off of:

Figure 18-3 -The capacitive reactance in Figure 18-3 is equal to the resistance at the critical frequency.

Figure 18-9 -Identify the filter circuit in Figure 18-9 above.

Quantities and Units

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Ohms Law

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Introduction to Alternating Current and Voltage

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