Question 1

Star #1 is approaching the Earth with speed v.Star #2 is receding from the Earth with the same speed v.Measurements of the same spectral line from each of the stars show Doppler shifts in frequency.The light from which star will have the larger magnitude shift in frequency?

Accepted Answer

A) star #1 
B) Both stars will have the same shift. 
C) The value of the speed must be known before an answer can be found. 
D) star #2

Question 2

An observer is moving in space toward a distant star at 50.0 km/s while the star is moving toward the observer at 180 km/s;the relative velocity being 230 km/s of approach.What relative change in frequency of the light from the star as seen by the observer? (The speed of light in space is 3.00 × 105 km/s).

Accepted Answer

A) 0.077% increase 
B) 0.077% decrease 
C) 0.026% increase 
D) 0.23% decrease 
E) 0.23% increase

Question 3

An AC series circuit contains a resistor of 30.0 Ω,a capacitor of 1.22 μF and an inductor of 154 mH.What frequency should be used to create a resonance condition in the circuit?

Accepted Answer

A) 3.49E+2 Hz 
B) 8.48E+2 Hz 
C) 9.21E+2 Hz 
D) 3.67E+2 Hz 
E) 7.35E+2 Hz

Question 4

An RLC circuit is connected across an AC power source.How are the maximum and rms voltages from the power source related?​

Accepted Answer

A) ​Δ​V​max =  ΔV​rms 
B) ​Δ​V​max = ΔV​rms/  
C) ​Δ​V​max = 2ΔV​rms 
D) ​Δ​V​max = ΔV​rms/2

Question 5

What is the effective (rms)current value for an AC current with an amplitude of 15.4 A?

Accepted Answer

A) 15.4 A 
B) 7.70 A 
C) 10.9 A 
D) 3.92 A 
E) 2.77 A

Question 6

A 100-kg spacecraft has a sail of area 300 m2 that is absorbing sunlight of intensity 800 W/m2.What is the resulting acceleration of the spacecraft?

Accepted Answer

A) 2.4 m/s2 
B) 2.7 × 10-6 m/s2 
C) 8.0 × 10-6 m/s2 
D) 3.8 × 10-5 m/s2

Question 7

What is the maximum value of the electric field E at 1.5 m from a 102-W light bulb radiating in all directions? (µ0 = 4π × 10−7 T⋅m/A,c = 3.00 × 108 m/s)

Accepted Answer

A) 5.2E+1 V/m 
B) 4.1E+3 V/m 
C) 2.7E+3 V/m 
D) 8.5E+2 V/m 
E) 3.2E+2 V/m

Question 8

Resonance occurs in an AC series circuit when which of the following conditions is met?

Accepted Answer

A) resistance equals capacitive reactance 
B) resistance equals inductive reactance 
C) capacitive reactance equals inductive reactance 
D) capacitive reactance equals zero

Question 9

Maxwell guessed that visible light was an electromagnetic wave because of its:

Accepted Answer

A) frequency. 
B) wavelength. 
C) speed. 
D) energy.

Question 10

In order of increasing frequency,which of the following is correct?

Accepted Answer

A) visible,radio,ultraviolet and x-ray 
B) infrared,visible,ultraviolet and gamma 
C) visible,gamma,ultraviolet and x-ray 
D) infrared,x-ray,visible and gamma

Question 11

Which of the following combinations of circuit components can be used to make a tuner for a radio,to select the desired frequency?

Accepted Answer

A) fixed inductor,variable resistor 
B) fixed resistor,variable inductor 
C) fixed inductor,variable capacitor 
D) fixed capacitor,variable resistor

Question 12

A resistor,inductor,and capacitor are connected in series,each with an effective (rms)voltage of 63 V,176 V,and 65 V,respectively.What is the magnitude of the phase angle in this circuit?

Accepted Answer

A) 30° 
B) 64° 
C) 59° 
D) 60° 
E) 69°

Question 13

In an RLC series circuit,if the AC frequency is decreased to a very small value,what value does the phase angle between the current and voltage approach?

Accepted Answer

A) 90° 
B) 0° 
C) -90° 
D) 45°

Question 14

A resistor and capacitor are connected in series with an applied AC voltage source.Separate voltmeter readings across the resistor and capacitor give values of 23 V and 29 V (rms),respectively.What is the effective (rms)voltage of the source?

Accepted Answer

A) 7.2 V 
B) 47 V 
C) 37 V 
D) 26 V 
E) 18 V

Question 15

In an RL circuit,which of the following is a possible magnitude of a phase angle?

Accepted Answer

A) 45° 
B) 315° 
C) 225° 
D) 135°

Question 16

A resistor,inductor and capacitor are connected in series,each with effective (rms)voltage of 80.0 V,160 V,and 84.0 V,respectively.If the resistor is rated at 15.0 Ω,what is the average power dissipated in the circuit?

Accepted Answer

A) 812 W 
B) 427 W 
C) 309 W 
D) 589 W 
E) 559 W

Question 17

A radio wave transmits 1.59 W/m2 average power per unit area.What is the peak value of the associated magnetic field? (μ0 = 4π × 10−7 T⋅m/A and c = 3.00 × 108 m/s)

Accepted Answer

A) 1.33E-14 T 
B) 3.46E+1 T 
C) 1.15E-7 T 
D) 7.28E-5 T 
E) ​8.16E-8 T

Question 18

An AC series circuit contains a resistor of 20.0 Ω,an inductor of 74.0 mH and a variable capacitor.If the frequency of the applied voltage is 423 Hz,to what setting should the capacitor be set if resonance is achieved?

Accepted Answer

A) 1.89E-5 F 
B) 7.66E-6 F 
C) 5.09E-6 F 
D) 1.91E-6 F 
E) 1.91E-5 F

Question 19

In an LCR series circuit with XL > XC,the phase angle between the current and voltage phasors is 30°.If the AC frequency doubles,what is the magnitude of the resulting phase angle?

Accepted Answer

A) 30° 
B) less than 30° 
C) more than 30° 
D) Additional information is needed to reach a determination.

Question 20

An engineer designed a transformer to convert 120 V (rms) to 6.0 V (rms). The number of turns in the primary is 540, and the secondary current is 610 mA at an output voltage of 6.0 V (rms). 
-How many turns are in the secondary?

Accepted Answer

A) 90 
B) 27 
C) 5 
D) 3 240

Exam 21: Alternating-Current Circuits and Electromagnetic Waves

Star #1 is approaching the Earth with speed v.Star #2 is receding from the Earth with the same speed v.Measurements of the same spectral line from each of the stars show Doppler shifts in frequency.The light from which star will have the larger magnitude shift in frequency?

An AC series circuit contains a resistor of 30.0 Ω,a capacitor of 1.22 μF and an inductor of 154 mH.What frequency should be used to create a resonance condition in the circuit?

An RLC circuit is connected across an AC power source.How are the maximum and rms voltages from the power source related?

What is the effective (rms) current value for an AC current with an amplitude of 15.4 A?

A 100-kg spacecraft has a sail of area 300 m² that is absorbing sunlight of intensity 800 W/m².What is the resulting acceleration of the spacecraft?

What is the maximum value of the electric field E at 1.5 m from a 102-W light bulb radiating in all directions? (µ₀ = 4π × 10−⁷ T⋅m/A,c = 3.00 × 10⁸ m/s)

Resonance occurs in an AC series circuit when which of the following conditions is met?

Maxwell guessed that visible light was an electromagnetic wave because of its:

In order of increasing frequency,which of the following is correct?

Which of the following combinations of circuit components can be used to make a tuner for a radio,to select the desired frequency?

A resistor,inductor,and capacitor are connected in series,each with an effective (rms) voltage of 63 V,176 V,and 65 V,respectively.What is the magnitude of the phase angle in this circuit?

In an RLC series circuit,if the AC frequency is decreased to a very small value,what value does the phase angle between the current and voltage approach?

A resistor and capacitor are connected in series with an applied AC voltage source.Separate voltmeter readings across the resistor and capacitor give values of 23 V and 29 V (rms) ,respectively.What is the effective (rms) voltage of the source?

In an RL circuit,which of the following is a possible magnitude of a phase angle?

A resistor,inductor and capacitor are connected in series,each with effective (rms) voltage of 80.0 V,160 V,and 84.0 V,respectively.If the resistor is rated at 15.0 Ω,what is the average power dissipated in the circuit?

A radio wave transmits 1.59 W/m² average power per unit area.What is the peak value of the associated magnetic field? (μ₀ = 4π × 10−⁷ T⋅m/A and c = 3.00 × 10⁸ m/s)

An AC series circuit contains a resistor of 20.0 Ω,an inductor of 74.0 mH and a variable capacitor.If the frequency of the applied voltage is 423 Hz,to what setting should the capacitor be set if resonance is achieved?

In an LCR series circuit with X_L > X_C,the phase angle between the current and voltage phasors is 30°.If the AC frequency doubles,what is the magnitude of the resulting phase angle?

An engineer designed a transformer to convert 120 V (rms) to 6.0 V (rms) . The number of turns in the primary is 540, and the secondary current is 610 mA at an output voltage of 6.0 V (rms) . -How many turns are in the secondary?

Exam 21: Alternating-Current Circuits and Electromagnetic Waves

Star #1 is approaching the Earth with speed v.Star #2 is receding from the Earth with the same speed v.Measurements of the same spectral line from each of the stars show Doppler shifts in frequency.The light from which star will have the larger magnitude shift in frequency?

An AC series circuit contains a resistor of 30.0 Ω,a capacitor of 1.22 μF and an inductor of 154 mH.What frequency should be used to create a resonance condition in the circuit?

An RLC circuit is connected across an AC power source.How are the maximum and rms voltages from the power source related?​

What is the effective (rms) current value for an AC current with an amplitude of 15.4 A?

A 100-kg spacecraft has a sail of area 300 m2 that is absorbing sunlight of intensity 800 W/m2.What is the resulting acceleration of the spacecraft?

What is the maximum value of the electric field E at 1.5 m from a 102-W light bulb radiating in all directions? (µ0 = 4π × 10−7 T⋅m/A,c = 3.00 × 108 m/s)

Resonance occurs in an AC series circuit when which of the following conditions is met?

Maxwell guessed that visible light was an electromagnetic wave because of its:

In order of increasing frequency,which of the following is correct?

Which of the following combinations of circuit components can be used to make a tuner for a radio,to select the desired frequency?

A resistor,inductor,and capacitor are connected in series,each with an effective (rms) voltage of 63 V,176 V,and 65 V,respectively.What is the magnitude of the phase angle in this circuit?

In an RLC series circuit,if the AC frequency is decreased to a very small value,what value does the phase angle between the current and voltage approach?

A resistor and capacitor are connected in series with an applied AC voltage source.Separate voltmeter readings across the resistor and capacitor give values of 23 V and 29 V (rms) ,respectively.What is the effective (rms) voltage of the source?

In an RL circuit,which of the following is a possible magnitude of a phase angle?

A resistor,inductor and capacitor are connected in series,each with effective (rms) voltage of 80.0 V,160 V,and 84.0 V,respectively.If the resistor is rated at 15.0 Ω,what is the average power dissipated in the circuit?

A radio wave transmits 1.59 W/m2 average power per unit area.What is the peak value of the associated magnetic field? (μ0 = 4π × 10−7 T⋅m/A and c = 3.00 × 108 m/s)

An AC series circuit contains a resistor of 20.0 Ω,an inductor of 74.0 mH and a variable capacitor.If the frequency of the applied voltage is 423 Hz,to what setting should the capacitor be set if resonance is achieved?

In an LCR series circuit with XL > XC,the phase angle between the current and voltage phasors is 30°.If the AC frequency doubles,what is the magnitude of the resulting phase angle?

An engineer designed a transformer to convert 120 V (rms) to 6.0 V (rms) . The number of turns in the primary is 540, and the secondary current is 610 mA at an output voltage of 6.0 V (rms) . -How many turns are in the secondary?

An RLC circuit is connected across an AC power source.How are the maximum and rms voltages from the power source related?

A 100-kg spacecraft has a sail of area 300 m² that is absorbing sunlight of intensity 800 W/m².What is the resulting acceleration of the spacecraft?

What is the maximum value of the electric field E at 1.5 m from a 102-W light bulb radiating in all directions? (µ₀ = 4π × 10−⁷ T⋅m/A,c = 3.00 × 10⁸ m/s)

A radio wave transmits 1.59 W/m² average power per unit area.What is the peak value of the associated magnetic field? (μ₀ = 4π × 10−⁷ T⋅m/A and c = 3.00 × 10⁸ m/s)

In an LCR series circuit with X_L > X_C,the phase angle between the current and voltage phasors is 30°.If the AC frequency doubles,what is the magnitude of the resulting phase angle?