Question 1

-If the frequency increases in Figure 10-1, the phase angle ________ and the impedance ________.

Accepted Answer

A) decreases, decreases 
B) decreases, increases 
C) increases, decreases 
D) increases, increases 
A) decreases, decreases 
B) decreases, increases 
C) increases, decreases 
D) increases, increases A

Question 2

The phasor combination of V   in an RC series circuit equals the source voltage.

Accepted Answer

A) True 
 B)False  True

Question 3

-What is the circuitʹs impedance in Figure 10-1?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)    B

Question 4

It has been determined that the phase shift of a given parallel RC circuit is lower than predicted. Which of the following most likely has caused this?

Accepted Answer

A) Resistance has decreased. 
B) The function generator frequency control has been accidentally moved to a lower frequency. 
C) The capacitance has decreased. 
D) could be A or C 
A) Resistance has decreased. 
B) The function generator frequency control has been accidentally moved to a lower frequency. 
C) The capacitance has decreased. 
D) could be A or C

Question 5

When the frequency applied to an RC circuit varies, the value of   varies.

Accepted Answer

A) True 
 B)False

Question 6

-If the input voltage increases to 50 V in Figure 10-3, what is the output voltage at the cutoff frequency?

Accepted Answer

A) 70.7 V 
B) 17.7 V 
C) 35.4 V 
D) 8.84 V 
A) 70.7 V 
B) 17.7 V 
C) 35.4 V 
D) 8.84 V

Question 7

-If the circuit in Figure 10-3 has an output voltage thatʹs too high at the cutoff frequency, ________.

Accepted Answer

A) the resistor has opened 
B) the resistor has shorted 
C) the capacitor has become leaky 
D) the capacitor has shorted 
A) the resistor has opened 
B) the resistor has shorted 
C) the capacitor has become leaky 
D) the capacitor has shorted

Question 8

-What change would increase the power factor in Figure 10-2?

Accepted Answer

A) Increasing the value of the capacitor 
B) Increasing the value of the resistor 
C) Decreasing the value of the capacitor 
D) Increasing the value of the source voltage 
A) Increasing the value of the capacitor 
B) Increasing the value of the resistor 
C) Decreasing the value of the capacitor 
D) Increasing the value of the source voltage

Question 9

An RC circuit can be used as a filter to eliminate selected frequencies.

Accepted Answer

A) True 
 B)False

Question 10

-If the operating frequency increases in Figure 10-1, how does the phase angle change?

Accepted Answer

A) It remains the name. 
B) It increases. 
C) It decreases. 
D) It changes to another quadrant. 
A) It remains the name. 
B) It increases. 
C) It decreases. 
D) It changes to another quadrant.

Question 11

If the true power is 100 W and the reactive power is 100 VAR, the apparent power is ________.

Accepted Answer

A) 141 W 
B) 200 VA 
C) 141 VA 
D) 100 VA 
A) 141 W 
B) 200 VA 
C) 141 VA 
D) 100 VA

Question 12

-If the source voltage is changed to 100 V in Figure 10-1, find the true power.

Accepted Answer

A) 22.9 mW 
B) 3.66 W 
C) 22.9 W 
D) 11 W 
A) 22.9 mW 
B) 3.66 W 
C) 22.9 W 
D) 11 W

Question 13

-If the resistance is reduced to   in Figure 10-3, the cutoff frequency equals ________.

Accepted Answer

A) 995 Hz 
B) 480 Hz 
C) 99 Hz 
D) 6250 Hz 
A) 995 Hz 
B) 480 Hz 
C) 99 Hz 
D) 6250 Hz

Question 14

-If the resistor value increases in Figure 10-2, then how does the total current change?

Accepted Answer

A) It increases. 
B) It decreases. 
C) It decreases to zero. 
D) It remains the same. 
A) It increases. 
B) It decreases. 
C) It decreases to zero. 
D) It remains the same.

Question 15

-If the frequency decreases in Figure 10-1, the phase angle ________ and the impedance ________.

Accepted Answer

A) decreases, increases 
B) decreases, decreases 
C) increases, increases 
D) increases, decreases 
A) decreases, increases 
B) decreases, decreases 
C) increases, increases 
D) increases, decreases

Question 16

The phase angle of an RC circuit varies inversely with frequency.

Accepted Answer

A) True 
 B)False

Question 17

As the frequency applied to an RC circuit increases, the impedance decreases.

Accepted Answer

A) True 
 B)False

Question 18

-How much voltage does the capacitor drop in Figure 10-2?

Accepted Answer

A) 20 V 
B) 19.94 V 
C) 59 mV 
D) 10 V 
A) 20 V 
B) 19.94 V 
C) 59 mV 
D) 10 V

Question 19

If there is   across the resistor and   across the capacitor in a series RC circuit, then the source voltage equals ________.

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 20

-What change would decrease the power factor in Figure 10-2?

Accepted Answer

A) increasing the value of the resistor 
B) decreasing the value of the capacitor 
C) increasing the value of Vs 
D) increasing the value of the capacitor 
A) increasing the value of the resistor 
B) decreasing the value of the capacitor 
C) increasing the value of Vs 
D) increasing the value of the capacitor

Exam 10: Magnetism and Electromagnetism

-If the frequency increases in Figure 10-1, the phase angle ________ and the impedance ________.

The phasor combination of V in an RC series circuit equals the source voltage.

-What is the circuitʹs impedance in Figure 10-1?

It has been determined that the phase shift of a given parallel RC circuit is lower than predicted. Which of the following most likely has caused this?

When the frequency applied to an RC circuit varies, the value of varies.

-If the input voltage increases to 50 V in Figure 10-3, what is the output voltage at the cutoff frequency?

-If the circuit in Figure 10-3 has an output voltage thatʹs too high at the cutoff frequency, ________.

-What change would increase the power factor in Figure 10-2?

An RC circuit can be used as a filter to eliminate selected frequencies.

-If the operating frequency increases in Figure 10-1, how does the phase angle change?

If the true power is 100 W and the reactive power is 100 VAR, the apparent power is ________.

-If the source voltage is changed to 100 V in Figure 10-1, find the true power.

-If the resistance is reduced to in Figure 10-3, the cutoff frequency equals ________.

-If the resistor value increases in Figure 10-2, then how does the total current change?

-If the frequency decreases in Figure 10-1, the phase angle ________ and the impedance ________.

The phase angle of an RC circuit varies inversely with frequency.

As the frequency applied to an RC circuit increases, the impedance decreases.

-How much voltage does the capacitor drop in Figure 10-2?

If there is across the resistor and across the capacitor in a series RC circuit, then the source voltage equals ________.

-What change would decrease the power factor in Figure 10-2?

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

Introduction to Alternating Current and Voltage

Capacitors

Inductors

Transformers

RC Circuits

RL Circuits

RlC Circuits and Resonance

Passive Filters

Circuit Theorems in Ac Analysis

Time Response of Reactive Circuits

Three-Phase Systems in Power Applications

Filters

-If the frequency increases in Figure 10-1, the phase angle and the impedance .

-If the frequency decreases in Figure 10-1, the phase angle and the impedance .