Question 1

In an oscillating LC circuit, the total stored energy is U.The maximum energy stored in the capacitor during one cycle is:

Accepted Answer

A)  U/2
B)   
C)  U
D)  U/(2   π\piπ  ) 
E)  U/  π\piπ

Question 2

An RLC circuit has a resistance of 200   Ω\OmegaΩ   and an inductance of 15 mH.Its oscillation frequency is 7000 Hz.At time t = 0 the current is 25 mA and there is no charge on the capacitor.After five complete cycles the current is:

Accepted Answer

A)  0 A
B)  1.8 * 10-6 A
C)  2.1 *10-4 A
D)  2.3 * 10-3 A
E)  2.5 * 10-2 A

Question 3

When the frequency of the oscillator in a series RLC circuit is doubled:

Accepted Answer

A)  the capacitive reactance is doubled
B)  the capacitive reactance is halved
C)  the impedance is doubled
D)  the current amplitude is doubled
E)  the current amplitude is halved

Question 4

The ideal meters shown read rms current and voltage.The average power delivered to the load is:

Accepted Answer

A)  definitely not equal to VI
B)  perhaps more than VI
C)  possibly equal to VI even if the load contains an inductor and a capacitor
D)  definitely less than VI
E)  zero as is the average of any sine wave

Question 5

In an oscillating LC circuit, the total stored energy is U and the maximum charge on the capacitor is Q.When the charge on the capacitor is Q/2, the energy stored in the inductor is:

Accepted Answer

A)  U/2
B)  U/4
C)  (4/3) U
D)  3U/2
E)  3U/4

Question 6

A capacitor in an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360  μ\muμ J.At a certain instant the energy in the capacitor is 40  μ\muμ J.At that instant what is the potential difference across the capacitor?

Accepted Answer

A)  0 V
B)  5 V
C)  10 V
D)  15 V
E)  20 V

Question 7

A power transmission line carries 400A of current at a voltage of 765 kV.If the line has a resistance of 29 µΩ/m, what is the rate at which energy is being dissipated in 800 km of line?

Accepted Answer

A)  0 W
B)  3.7 kW
C)  310 kW
D)  3.7 MW
E)  310 MW

Question 8

An RLC circuit has a capacitance of 12   μ\muμ  F, an inductance of 25 mH, and a resistance of 60   Ω\OmegaΩ  .The current oscillates with an angular frequency of:

Accepted Answer

A)  1.2 * 103 rad/s
B)  1.4 * 103 rad/s
C)  1.8 * 103 rad/s
D)  2.2 * 103 rad/s
E)  2.6 * 103 rad/s

Question 9

In an RLC series circuit, which is connected to a source of emf   mcos(   t) , the current lags the voltage by 45 °  if: A)  R = 1/   C -    L  B)  R = 1/   L -    C  C)  R =     L - 1/   C  D)  R =    C - 1/   L  E)     L = 1/   C " class="answers-bank-image d-inline" rel="preload" >   mcos(   mcos(   t) , the current lags the voltage by 45 °  if: A)  R = 1/   C -    L  B)  R = 1/   L -    C  C)  R =     L - 1/   C  D)  R =    C - 1/   L  E)     L = 1/   C " class="answers-bank-image d-inline" rel="preload" > t) , the current lags the voltage by 45 °  if:

Accepted Answer

A)  "R = 1/   mcos(   t) , the current lags the voltage by 45 °  if: 
A)   R = 1/   C -    L  
B)   R = 1/   L -    C  
C)   R =     L - 1/   C  
D)   R =    C - 1/   L  
E)      L = 1/   C " class="answers-bank-image d-inline" rel="preload" > C -   L"
B)  "R = 1/  L -   C"
C)  "R =    L - 1/  C"
D)  "R =   C - 1/  L"
E)  "  L = 1/  C"

Question 10

An RLC series circuit has R = 4   Ω\OmegaΩ  , XC = 3   Ω\OmegaΩ  , and XL = 6  Ω\OmegaΩ  .The impedance of this circuit is:

Accepted Answer

A)  5  Ω\OmegaΩ  
B)  7   Ω\OmegaΩ  
C)  7.8   Ω\OmegaΩ  
D)  9.8   Ω\OmegaΩ  
E)  13  (\Omega\)

Question 11

The impedance of the circuit shown is:

Accepted Answer

A)  21  Ω\OmegaΩ  
B)  50   Ω\OmegaΩ  
C)  63   Ω\OmegaΩ  
D)  65   Ω\OmegaΩ  
E)  98   Ω\OmegaΩ

Question 12

A charged capacitor and an inductor are connected in series.At time t = 0 the current is zero, but the capacitor is charged.If T is the period of the resulting oscillations, the next time, after t = 0 that the voltage across the inductor is a maximum is:

Accepted Answer

A)  T/4
B)  T/2
C)  T
D)  3T/2
E)  2T

Question 13

An LC circuit has an inductance of 20 mH and a capacitance of 5.0  μ\muμ F.At time t = 0 the charge on the capacitor is 3.0  μ\muμ C and the current is 7.0 mA.The total energy is:

Accepted Answer

A)  4.1 * 10-7 J
B)  4.9 * 10-7 J
C)  9.0 * 10-7 J
D)  1.4 * 10-6 J
E)  2.8 *10-6 J

Question 14

An LC circuit has an inductance of 20 mH and a capacitance of 5.0  μ\muμ F.If the charge amplitude is 40  μ\muμ C, what is the current amplitude?

Accepted Answer

A)  0.025 A
B)  0.13 A
C)  1.0 A
D)  7.9 A
E)  400 A

Question 15

The rms value of an ac current is:

Accepted Answer

A)  its peak value
B)  its average value
C)  that steady current that produces the same rate of heating in a resistor
D)  that steady current that will charge a battery at the same rate
E)  zero

Question 16

Radio receivers are usually tuned by adjusting the capacitor of an LC circuit.If C = C1 for a frequency of 600 kHz, then for a frequency of 1200 kHz one must adjust C to:

Accepted Answer

A)  C1/2
B)  C1/4
C)  2C1
D)  4C1
E)   1 for a frequency of 600 kHz, then for a frequency of 1200 kHz one must adjust C to: 
A)  C1/2 
B)  C1/4 
C)  2C1 
D)  4C1 
E)    " class="answers-bank-image d-inline" rel="preload" >

Question 17

We desire to make an LC circuit that oscillates at 100 Hz using an inductance of 2.5 H.We also need a capacitance of:

Accepted Answer

A)  1 F
B)  1 mF
C)  1  μ\mu μ F
D)  1 nF
E)  1 pF

Question 18

A series circuit consists of a 15-  Ω\OmegaΩ  resistor, a 25-mH inductor, and a 35-  Ω\OmegaΩ   capacitor.If the frequency is 100 Hz the power factor is:

Accepted Answer

A)  0
B)  0.20
C)  0.45
D)  0.65
E)  1.0

Question 19

The impedance of an RLC series circuit is definitely increased if:

Accepted Answer

A)  C decreases
B)  L increases
C)  L decreases
D)  R increases
E)  R decreases

Question 20

In the diagram, the function y(t) = ymsin( msin(   t) is plotted as a solid curve.The other three curves have the form y(t) = ymsin(   t +    ) , where     is between -   \pi  /2 and +  \pi  /2.Rank the curves according to the value of     , from the most negative to the most positive.   A) 1, 2, 3 B) 2, 3, 1 C) 3, 2, 1 D) 1, 3, 2 E) 2, 1, 3 " class="answers-bank-image d-inline" rel="preload" > t) is plotted as a solid curve.The other three curves have the form y(t) = ymsin(  t +   ) , where    is between -   π\piπ  /2 and +  π\piπ  /2.Rank the curves according to the value of    , from the most negative to the most positive.

Accepted Answer

A)  1, 2, 3
B)  2, 3, 1
C)  3, 2, 1
D)  1, 3, 2
E)  2, 1, 3

Exam 31: Electromagnetic Oscillations and Alternating Current

An RLC circuit has a capacitance of 12 $\mu$ F, an inductance of 25 mH, and a resistance of 60 $\Omega$ .The current oscillates with an angular frequency of:

Correct Answer
verified

We desire to make an LC circuit that oscillates at 100 Hz using an inductance of 2.5 H.We also need a capacitance of:

Correct Answer
verified

The impedance of the circuit shown is: $The impedance of the circuit shown is: A) 21 \Omega B) 50 \Omega C) 63 \Omega D) 65 \Omega E) 98 \Omega$

Correct Answer
verified

In an oscillating LC circuit, the total stored energy is U.The maximum energy stored in the capacitor during one cycle is:

Correct Answer
verified

When the frequency of the oscillator in a series RLC circuit is doubled:

Correct Answer
verified

The impedance of an RLC series circuit is definitely increased if:

Correct Answer
verified

The rms value of an ac current is:

Correct Answer
verified

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 $\mu$ F.At time t = 0 the charge on the capacitor is 3.0 $\mu$ C and the current is 7.0 mA.The total energy is:

Correct Answer
verified

A capacitor in an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360 $\mu$ J.At a certain instant the energy in the capacitor is 40 $\mu$ J.At that instant what is the potential difference across the capacitor?

Correct Answer
verified

An RLC series circuit has R = 4 $\Omega$ , X_C = 3 $\Omega$ , and X_L = 6 $\Omega$ .The impedance of this circuit is:

Correct Answer
verified

A series circuit consists of a 15- $\Omega$ resistor, a 25-mH inductor, and a 35- $\Omega$ capacitor.If the frequency is 100 Hz the power factor is:

Correct Answer
verified

In an oscillating LC circuit, the total stored energy is U and the maximum charge on the capacitor is Q.When the charge on the capacitor is Q/2, the energy stored in the inductor is:

Correct Answer
verified

Correct Answer
verified

A charged capacitor and an inductor are connected in series.At time t = 0 the current is zero, but the capacitor is charged.If T is the period of the resulting oscillations, the next time, after t = 0 that the voltage across the inductor is a maximum is:

Correct Answer
verified

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 $\mu$ F.If the charge amplitude is 40 $\mu$ C, what is the current amplitude?

Correct Answer
verified

A power transmission line carries 400A of current at a voltage of 765 kV.If the line has a resistance of 29 µΩ/m, what is the rate at which energy is being dissipated in 800 km of line?

Correct Answer
verified

An RLC circuit has a resistance of 200 $\Omega$ and an inductance of 15 mH.Its oscillation frequency is 7000 Hz.At time t = 0 the current is 25 mA and there is no charge on the capacitor.After five complete cycles the current is:

Correct Answer
verified

In an RLC series circuit, which is connected to a source of emf _mcos( t) , the current lags the voltage by 45 ° if:

Correct Answer
verified

The ideal meters shown read rms current and voltage.The average power delivered to the load is:

Correct Answer
verified

Radio receivers are usually tuned by adjusting the capacitor of an LC circuit.If C = C₁ for a frequency of 600 kHz, then for a frequency of 1200 kHz one must adjust C to:

Correct Answer
verified

Exam 31: Electromagnetic Oscillations and Alternating Current

An RLC circuit has a capacitance of 12 μ\muμ F, an inductance of 25 mH, and a resistance of 60 Ω\OmegaΩ .The current oscillates with an angular frequency of:

Correct AnswerverifiedShow Answer

We desire to make an LC circuit that oscillates at 100 Hz using an inductance of 2.5 H.We also need a capacitance of:

Correct AnswerverifiedShow Answer

The impedance of the circuit shown is:

Correct AnswerverifiedShow Answer

In an oscillating LC circuit, the total stored energy is U.The maximum energy stored in the capacitor during one cycle is:

Correct AnswerverifiedShow Answer

When the frequency of the oscillator in a series RLC circuit is doubled:

Correct AnswerverifiedShow Answer

The impedance of an RLC series circuit is definitely increased if:

Correct AnswerverifiedShow Answer

The rms value of an ac current is:

Correct AnswerverifiedShow Answer

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 μ\muμ F.At time t = 0 the charge on the capacitor is 3.0 μ\muμ C and the current is 7.0 mA.The total energy is:

Correct AnswerverifiedShow Answer

A capacitor in an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360 μ\muμ J.At a certain instant the energy in the capacitor is 40 μ\muμ J.At that instant what is the potential difference across the capacitor?

Correct AnswerverifiedShow Answer

An RLC series circuit has R = 4 Ω\OmegaΩ , XC = 3 Ω\OmegaΩ , and XL = 6 Ω\OmegaΩ .The impedance of this circuit is:

Correct AnswerverifiedShow Answer

A series circuit consists of a 15- Ω\OmegaΩ resistor, a 25-mH inductor, and a 35- Ω\OmegaΩ capacitor.If the frequency is 100 Hz the power factor is:

Correct AnswerverifiedShow Answer

In an oscillating LC circuit, the total stored energy is U and the maximum charge on the capacitor is Q.When the charge on the capacitor is Q/2, the energy stored in the inductor is:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A charged capacitor and an inductor are connected in series.At time t = 0 the current is zero, but the capacitor is charged.If T is the period of the resulting oscillations, the next time, after t = 0 that the voltage across the inductor is a maximum is:

Correct AnswerverifiedShow Answer

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 μ\muμ F.If the charge amplitude is 40 μ\muμ C, what is the current amplitude?

Correct AnswerverifiedShow Answer

A power transmission line carries 400A of current at a voltage of 765 kV.If the line has a resistance of 29 µΩ/m, what is the rate at which energy is being dissipated in 800 km of line?

Correct AnswerverifiedShow Answer

An RLC circuit has a resistance of 200 Ω\OmegaΩ and an inductance of 15 mH.Its oscillation frequency is 7000 Hz.At time t = 0 the current is 25 mA and there is no charge on the capacitor.After five complete cycles the current is:

Correct AnswerverifiedShow Answer

In an RLC series circuit, which is connected to a source of emf mcos( t) , the current lags the voltage by 45 ° if:

Correct AnswerverifiedShow Answer

The ideal meters shown read rms current and voltage.The average power delivered to the load is:

Correct AnswerverifiedShow Answer

Radio receivers are usually tuned by adjusting the capacitor of an LC circuit.If C = C1 for a frequency of 600 kHz, then for a frequency of 1200 kHz one must adjust C to:

Correct AnswerverifiedShow Answer

An RLC circuit has a capacitance of 12 $\mu$ F, an inductance of 25 mH, and a resistance of 60 $\Omega$ .The current oscillates with an angular frequency of:

Correct Answer
verified

Correct Answer
verified

The impedance of the circuit shown is: $The impedance of the circuit shown is: A) 21 \Omega B) 50 \Omega C) 63 \Omega D) 65 \Omega E) 98 \Omega$

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 $\mu$ F.At time t = 0 the charge on the capacitor is 3.0 $\mu$ C and the current is 7.0 mA.The total energy is:

Correct Answer
verified

A capacitor in an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360 $\mu$ J.At a certain instant the energy in the capacitor is 40 $\mu$ J.At that instant what is the potential difference across the capacitor?

Correct Answer
verified

An RLC series circuit has R = 4 $\Omega$ , X_C = 3 $\Omega$ , and X_L = 6 $\Omega$ .The impedance of this circuit is:

Correct Answer
verified

A series circuit consists of a 15- $\Omega$ resistor, a 25-mH inductor, and a 35- $\Omega$ capacitor.If the frequency is 100 Hz the power factor is:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 $\mu$ F.If the charge amplitude is 40 $\mu$ C, what is the current amplitude?

Correct Answer
verified

Correct Answer
verified

An RLC circuit has a resistance of 200 $\Omega$ and an inductance of 15 mH.Its oscillation frequency is 7000 Hz.At time t = 0 the current is 25 mA and there is no charge on the capacitor.After five complete cycles the current is:

Correct Answer
verified

In an RLC series circuit, which is connected to a source of emf _mcos( t) , the current lags the voltage by 45 ° if:

Correct Answer
verified

Correct Answer
verified

Radio receivers are usually tuned by adjusting the capacitor of an LC circuit.If C = C₁ for a frequency of 600 kHz, then for a frequency of 1200 kHz one must adjust C to:

Correct Answer
verified