Question 1

-Given the drawing in Figure 11-2, and the Time-per-division knob is set to 1.0 ms/Div, what is the frequency of Waveform A?

Accepted Answer

A)  2 kHz 
B)  400 Hz 
C)  100 Hz 
D)  5 kHz 
A)  2 kHz 
B)  400 Hz 
C)  100 Hz 
D)  5 kHz B

Question 2

Phasors are a convenient graphic way of representing sine wave voltages in terms of their:

Accepted Answer

A)  magnitude and frequency 
B)  magnitude and amplitude 
C)  magnitude and period 
D)  magnitude and phase 
A)  magnitude and frequency 
B)  magnitude and amplitude 
C)  magnitude and period 
D)  magnitude and phase D

Question 3

Find the frequency of a periodic wave that has a period of one hour.

Accepted Answer

A)  0.278 mHz 
B)  27.8 mHz 
C)  2.78 mHz 
D)  278 mHz 
A)  0.278 mHz 
B)  27.8 mHz 
C)  2.78 mHz 
D)  278 mHz A

Question 4

What angle in degrees is equivalent to n/3 radians?

Accepted Answer

A)  60° 
B)  90° 
C)  120° 
D)  30° 
A)  60° 
B)  90° 
C)  120° 
D)  30°

Question 5

In a circuit that contains a dc voltage source of 15 V and an ac voltage source of 50 Vp and a resistive load, what would be the maximum and minimum voltage measured across the resistive load?

Accepted Answer

A)  VMAX = zero V, VMIN = 35 V 
B)  VMAX = 65 V, VMIN = zero V 
C)  VMAX = 35 V, VMIN = 65 V 
D)  VMAX = 65 V, VMIN = 35 V 
A)  VMAX = zero V, VMIN = 35 V 
B)  VMAX = 65 V, VMIN = zero V 
C)  VMAX = 35 V, VMIN = 65 V 
D)  VMAX = 65 V, VMIN = 35 V

Question 6

How much time has elapsed when the waveform in Figure 11-4 reaches its rms value?

Accepted Answer

A)  0.25 mS 
B)  0.707 mS 
C)  0.5 mS 
D)  0.125 mS 
A)  0.25 mS 
B)  0.707 mS 
C)  0.5 mS 
D)  0.125 mS

Question 7

-Refer to Figure 11-3. Which of the following statements is correct?

Accepted Answer

A)  Waveform A lags Waveform B 
B)  Waveform A leads Waveform B. 
A)  Waveform A lags Waveform B 
B)  Waveform A leads Waveform B.

Question 8

What is the angular velocity of a phasor representing a sine wave with a frequency of 1.4 kHz?

Accepted Answer

A)  440 rad/s 
B)  4398 rad/s 
C)  8796 rad/s 
D)  880 rad/s 
A)  440 rad/s 
B)  4398 rad/s 
C)  8796 rad/s 
D)  880 rad/s

Question 9

The instantaneous value of a sine wave is:

Accepted Answer

A)  constantly changing 
B)  0.707 of its peak value. 
C)  equivalent to a like DC value 
D)  equal to 1.414 of the rms value. 
A)  constantly changing 
B)  0.707 of its peak value. 
C)  equivalent to a like DC value 
D)  equal to 1.414 of the rms value.

Question 10

The negative alternation of a sine wave of current indicates that:

Accepted Answer

A)  power in the circuit will be less during this time. 
B)  the current has changed direction. 
C)  the current is the opposite direction and polarity across components changes. 
D)  it is different in amplitude from its positive alternation. 
A)  power in the circuit will be less during this time. 
B)  the current has changed direction. 
C)  the current is the opposite direction and polarity across components changes. 
D)  it is different in amplitude from its positive alternation.

Question 11

The is defined as the time the output is active divided by the total period it could possibly be active.

Accepted Answer

A)  active ratio 
B)  duty cycle 
C)  pulse width 
D)  on time 
A)  active ratio 
B)  duty cycle 
C)  pulse width 
D)  on time

Question 12

The opposite side of a right triangle is equal to the hypotenuse times the sine of the angle 0.

Accepted Answer

A) True 
 B)False

Question 13

-You count 5 divisions on the horizontal axis on the scope. The Time-per-division knob is set to 1.0 ms/Div. Given the drawing in Figure 11-2, what is the frequency of Waveform B?

Accepted Answer

A)  0.2 kHz 
B)  0.5 kHz 
C)  1 kHz 
D)  5 kHz 
A)  0.2 kHz 
B)  0.5 kHz 
C)  1 kHz 
D)  5 kHz

Question 14

The time base control of the oscilloscope does which of the following?

Accepted Answer

A)  adjusts the vertical scale 
B)  shows you the current time of day 
C)  sends a clock pulse to the probe 
D)  sets the amount of time represented by the horizontal width of the screen 
A)  adjusts the vertical scale 
B)  shows you the current time of day 
C)  sends a clock pulse to the probe 
D)  sets the amount of time represented by the horizontal width of the screen

Question 15

The equation for finding the frequency, when the period is known is:

Accepted Answer

A)  f = 1/T 
B)  T = 0.707f 
C)  T = 1/f 
D)  T = n/2f) 
A)  f = 1/T 
B)  T = 0.707f 
C)  T = 1/f 
D)  T = n/2f)

Question 16

A complete sine wave contains:

Accepted Answer

A)  3n/2 radians 
B)  n radians 
C)  n/2 radians 
D)  2n radians 
A)  3n/2 radians 
B)  n radians 
C)  n/2 radians 
D)  2n radians

Question 17

The rate of change of a voltage sine wave is due to the change in flux density.

Accepted Answer

A) True 
 B)False

Question 18

A four-pole generator has a rotation speed of 400 rps. Determine the frequency of the output voltage.

Accepted Answer

A)  200 Hz 
B)  400 Hz 
C)  800 Hz 
D)  1600 Hz 
A)  200 Hz 
B)  400 Hz 
C)  800 Hz 
D)  1600 Hz

Question 19

There are 360 degrees in a complete cycle of a sine wave.

Accepted Answer

A) True 
 B)False

Question 20

A phasor represents a time-varying quantity in terms of both magnitude and direction.

Accepted Answer

A) True 
 B)False

Exam 11: Introduction to Alternating Current and Voltage

-Given the drawing in Figure 11-2, and the Time-per-division knob is set to 1.0 ms/Div, what is the frequency of Waveform A?

Phasors are a convenient graphic way of representing sine wave voltages in terms of their:

Find the frequency of a periodic wave that has a period of one hour.

What angle in degrees is equivalent to n/3 radians?

In a circuit that contains a dc voltage source of 15 V and an ac voltage source of 50 Vp and a resistive load, what would be the maximum and minimum voltage measured across the resistive load?

How much time has elapsed when the waveform in Figure 11-4 reaches its rms value?

-Refer to Figure 11-3. Which of the following statements is correct?

What is the angular velocity of a phasor representing a sine wave with a frequency of 1.4 kHz?

The instantaneous value of a sine wave is:

The negative alternation of a sine wave of current indicates that:

The is defined as the time the output is active divided by the total period it could possibly be active.

The opposite side of a right triangle is equal to the hypotenuse times the sine of the angle 0.

-You count 5 divisions on the horizontal axis on the scope. The Time-per-division knob is set to 1.0 ms/Div. Given the drawing in Figure 11-2, what is the frequency of Waveform B?

The time base control of the oscilloscope does which of the following?

The equation for finding the frequency, when the period is known is:

A complete sine wave contains:

The rate of change of a voltage sine wave is due to the change in flux density.

A four-pole generator has a rotation speed of 400 rps. Determine the frequency of the output voltage.

There are 360 degrees in a complete cycle of a sine wave.

A phasor represents a time-varying quantity in terms of both magnitude and direction.

Quantities and Units

Voltage, Current, and Resistance

Ohms Law

Energy and Power

Series Circuits

Parallel Circuits

Series-Parallel Circuits

Circuit Theorems and Conversions

Branch, Loop, and Node Analyses

Magnetism and Electromagnetism

Capacitors

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Rlc Circuits and Resonance

Passive Filters

Circuit Theorems in Ac Analysis

Time Response of Reactive Circuits

Three-Phase Systems in Power Applications

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