# Quiz 31: Electromagnetic Oscillations and Alternating Current

Physics & Astronomy

Q 1Q 1

An LC circuit has an inductance of 15 mH and a capacitance of 10 F.At one instant the charge on the capacitor is 25 C.At that instant the current is changing at the rate:
A)0 A/s
B)1.7 10

^{-}^{7}A/s C)5.9 10^{-3}A/s D)3.8 10^{-2}A/s E)170 A/sFree

Multiple Choice

E

Q 2Q 2

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

Free

Multiple Choice

B

Q 3Q 3

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 energy stored in the magnetic field of the inductor is a maximum is:
A)T/4
B)T/2
C)T
D)3T/2
E)2T

Free

Multiple Choice

A

Q 4Q 4

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 energy stored in the electric field of the capacitor is a maximum is:
A)T/4
B)T/2
C)T
D)3T/2
E)2T

Free

Multiple Choice

Free

Multiple Choice

Q 6Q 6

Consider the mechanical system consisting of two springs and a block, as shown.Which one of the five electrical circuits (I, II, III, IV, V)is the analog of the mechanical system?
A)I
B)II
C)III
D)IV
E)V

Free

Multiple Choice

Q 7Q 7

A 150-g block on the end of a spring with a spring constant of 35 N/m is pulled aside 25 cm and released from rest.In the electrical analog the initial charge on the capacitor is:
A)0.15 C
B)0.25 C
C)8.8 C
D)15 C
E)35 C

Free

Multiple Choice

Q 8Q 8

A 150-g block on the end of a spring with a spring constant of 35 N/m is pulled aside 25 cm and released from rest.In the electrical analog the maximum charge on the capacitor is 0.25 C.The maximum current in the LC circuit is:
A)0.025 A
B)0.12 A
C)3.8 A
D)5.3 A
E)40 A

Free

Multiple Choice

Q 9Q 9

Which of the following has the greatest effect in decreasing the oscillation frequency of an LC circuit? Using instead:
A)L/2 and C/2
B)L/2 and 2C
C)2L and C/2
D)2L and 2C
E)none of these

Free

Multiple Choice

Q 10Q 10

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:
A)1 F
B)1 mF
C)1 F
D)1 nF
E)1 pF

Free

Multiple Choice

Q 11Q 11

An LC circuit consists of a 1 F capacitor and a 4 mH inductor.Its oscillation frequency is approximately:
A)0.025 Hz
B)25 Hz
C)60 Hz
D)2500 Hz
E)16,000 Hz

Free

Multiple Choice

Q 12Q 12

An LC circuit has an oscillation frequency of 10

^{5}Hz.If C = 0.1 F, then L must be about: A)10 mH B)1 mH C)25 H D)2.5 H E)1 pHFree

Multiple Choice

Q 13Q 13

In the circuit shown, switch S is first pushed up to charge the capacitor.When S is then pushed down, the current in the circuit will oscillate at a frequency of:
A)0.010 Hz
B)12.5 Hz
C)320 Hz
D)2000 Hz
E)depends on V

_{0}Free

Multiple Choice

Q 14Q 14

An LC series circuit with an inductance L and a capacitance C has an oscillation frequency f.If we now take two of those inductors, each with inductance L, and two of the capacitors, each with capacitance C, and wire them all in series to make a new circuit, its oscillation frequency will be:
A)f/4
B)f/2
C)f
D)2f
E)4f

Free

Multiple Choice

Q 15Q 15

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 charge on the capacitor is a maximum is:
A)T/4
B)T/2
C)T
D)3T/2
E)2T

Free

Multiple Choice

Q 16Q 16

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 current is a maximum is:
A)T/4
B)T/2
C)T
D)3T/2
E)2T

Free

Multiple Choice

Q 17Q 17

An LC circuit has an inductance of 20 mH and a capacitance of 5.0 F.If the charge amplitude is 40 C, what is the current amplitude?
A)0.025 A
B)0.13 A
C)1.0 A
D)7.9 A
E)400 A

Free

Multiple Choice

Q 18Q 18

A capacitor in an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360 J.At a certain instant the energy in the capacitor is 40 J.At that instant what is the potential difference across the capacitor?
A)0 V
B)5 V
C)10 V
D)15 V
E)20 V

Free

Multiple Choice

Q 19Q 19

A capacitor in an LC oscillator has a maximum potential difference of 15 V and a maximum energy of 360 J.At a certain instant the energy in the capacitor is 40 J.At that instant what is the emf induced in the inductor?
A)0 V
B)5 V
C)10 V
D)15 V
E)20 V

Free

Multiple Choice

Q 20Q 20

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

Free

Multiple Choice

Q 21Q 21

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

Multiple Choice

Q 22Q 22

The total energy in an LC circuit is 5.0 10

^{-6}J.If C = 15 F the maximum charge on the capacitor is: A)0.82 C B)8.5 C C)12 C D)17 C E)24 CFree

Multiple Choice

Q 23Q 23

The total energy in an LC circuit is 5.0 10

^{-6}J.If L = 25 mH the maximum current is: A)10 mA B)14 mA C)20 mA D)28 mA E)40 mAFree

Multiple Choice

Q 24Q 24

At time t = 0 the charge on the 50-F capacitor in an LC circuit is 15 C and there is no current.If the inductance is 20 mH the maximum current is:
A)15 nA
B)15 A
C)6.7 mA
D)15 mA
E)15 A

Free

Multiple Choice

Q 25Q 25

An LC circuit has a capacitance of 30 F and an inductance of 15 mH.At time t = 0 the charge on the capacitor is 10 C and the current is 20 mA.The maximum charge on the capacitor is:
A)8.9 C
B)10 C
C)12 C
D)17 C
E)24 C

Free

Multiple Choice

Q 26Q 26

An LC circuit has a capacitance of 30 F and an inductance of 15 mH.At time t = 0 the charge on the capacitor is 10 C and the current is 20 mA.The maximum current is:
A)15 mA
B)20 mA
C)25 mA
D)35 mA
E)42 mA

Free

Multiple Choice

Q 27Q 27

An RLC circuit has a resistance of 200 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:
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}AFree

Multiple Choice

Q 28Q 28

The rapid exponential decay in just a few cycles of the charge on the plates of capacitor in an RLC circuit might due to:
A)a large inductance
B)a large capacitance
C)a small capacitance
D)a large resistance
E)a small resistance

Free

Multiple Choice

Q 29Q 29

An RLC circuit has a capacitance of 12 F, an inductance of 25 mH, and a resistance of 60 .The current oscillates with an angular frequency of:
A)1.2 10

^{3}rad/s B)1.4 10^{3}rad/s C)1.8 10^{3}rad/s D)2.2 10^{3}rad/s E)2.6 10^{3}rad/sFree

Multiple Choice

Q 30Q 30

An RLC circuit has a resistance of 200 an inductance of 15 mH, and a capacitance of 34 nF.At time t = 0 the charge on the capacitor is 25 µC and there is no current flowing.After five complete cycles the energy stored in the capacitor is:
A)0.64 µJ
B)77 µJ
C)0.49 mJ
D)1.8 mJ
E)9.2 mJ

Free

Multiple Choice

Q 31Q 31

The angular frequency of a certain RLC series circuit is

_{0}.A source of sinusoidal emf, with angular frequency 2_{0}, is inserted into the circuit.After transients die out the angular frequency of the current oscillations is: A)_{0}/2 B)_{0}C)1.5_{0 }D)2_{0}E)3_{0}Free

Multiple Choice

Q 32Q 32

The angular frequency of a certain RLC series circuit is

_{0}.A source of sinusoidal emf, with angular frequency , is inserted into the circuit and is varied while the amplitude of the source is held constant.For which of the following values of is the amplitude of the current oscillations the greatest? A)_{0}/5 B)_{0}/2 C)_{0}D)2_{0}E)None of them (they all produce the same current amplitude)Free

Multiple Choice

Q 33Q 33

A 35-F capacitor is connected to an ac source of emf with a frequency of 250 Hz and a maximum emf of 20 V.If the voltage across the capacitor is zero at time t = 0, what is the voltage at time t = 3.0 ms? Assume the phase constant is zero.
A)−20 V
B)−10 V
C)0 V
D)10 V
E)20 V

Free

Multiple Choice

Q 34Q 34

A 45-mH inductor is connected to an ac source of emf with a frequency of 250 Hz and a maximum emf of 20 V.If the voltage across the inductor is zero at time t = 0, what is the voltage at time t = 2.0 ms? Assume the phase constant is zero.
A)−20 V
B)−10 V
C)0 V
D)10 V
E)20 V

Free

Multiple Choice

Q 35Q 35

A 35-F capacitor is connected to an ac source of emf with a frequency of 400 Hz and a maximum emf of 20 V.The maximum current is:
A)0 A
B)0.28 A
C)1.8 A
D)230 A
E)1400 A

Free

Multiple Choice

Q 36Q 36

A 45-mH inductor is connected to an ac source of emf with a frequency of 400 Hz and a maximum emf of 20 V.The maximum current is:
A)0 A
B)0.18 A
C)1.1 A
D)360 A
E)2300 A

Free

Multiple Choice

Q 37Q 37

The reactance of a 35-F capacitor connected to a 400-Hz generator is:
A)0 Ω
B)0.014 Ω
C)0.088 Ω
D)11 Ω
E)71 Ω

Free

Multiple Choice

Q 38Q 38

In the diagram, the function y(t)= y

_{m}sin(t)is plotted as a solid curve.The other three curves have the form y(t)= y_{m}sin(t + ), where is between -/2 and +/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, 3Free

Multiple Choice

Q 39Q 39

A resistor, an inductor, and a capacitor are connected in parallel to a sinusoidal source of emf.Which of the following is true?
A)The currents in all branches are in phase.
B)The potential differences across all branches are in phase.
C)The current in the capacitor branch leads the current in the inductor branch by 1/4 cycle.
D)The potential difference across the capacitor branch leads the potential difference across the inductor branch by 1/4 cycle.
E)The current in the capacitor branch lags the current in the inductor branch by 1/4 cycle.

Free

Multiple Choice

Q 40Q 40

The impedance of an RLC series circuit is definitely increased if:
A)C decreases
B)L increases
C)L decreases
D)R increases
E)R decreases

Free

Multiple Choice

Free

Multiple Choice

Q 42Q 42

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

Free

Multiple Choice

Q 43Q 43

In an RLC series circuit, the source voltage is leading the current at a given frequency f.If f is lowered slightly, then the circuit impedance will:
A)increase
B)decrease
C)remain the same
D)cannot answer without knowing the amplitude of the source voltage
E)cannot answer without knowing whether the phase angle is larger or smaller than 45

Free

Multiple Choice

Q 44Q 44

An RLC series circuit has R = 4 , X

_{C}= 3 , and X_{L}= 6 .The impedance of this circuit is: A)5 B)7 C)7.8 D)9.8 E)13 Free

Multiple Choice

Q 45Q 45

A coil has a resistance of 60 and an impedance of 100 .Its reactance is:
A)40
B)60
C)80
D)117
E)160

Free

Multiple Choice

Q 46Q 46

When the amplitude of the oscillator in a series RLC circuit is doubled:
A)the impedance is doubled
B)the voltage across the capacitor is halved
C)the capacitive reactance is halved
D)the power factor is doubled
E)the current amplitude is doubled

Free

Multiple Choice

Q 47Q 47

An electric motor, under load, has an effective resistance of 30 and an inductive reactance of 40 .When powered by a source with a maximum voltage of 420 V, the maximum current is:
A)6.0 A
B)8.4 A
C)10.5 A
D)12 A
E)14 A

Free

Multiple Choice

Q 48Q 48

An ac generator producing 10 V (rms)at 200 rad/s is connected in series with a 50- resistor, a 400-mH inductor, and a 200-F capacitor.The rms current is:
A)0.125 A
B)0.135 A
C)0.18 A
D)0.20 A
E)0.40 A

Free

Multiple Choice

Q 49Q 49

An ac generator producing 10 V (rms)at 200 rad/s is connected in series with a 50- resistor, a 400-mH inductor, and a 200-F capacitor.The rms voltage across the resistor is:
A)2.5 V
B)3.4 V
C)6.7 V
D)10.0 V
E)10.8 V

Free

Multiple Choice

Q 50Q 50

An ac generator producing 10 V (rms)at 200 rad/s is connected in series with a 50- resistor, a 400-mH inductor, and a 200-F capacitor.The rms voltage across the capacitor is:
A)2.5 V
B)3.4 V
C)6.7 V
D)10.0 V
E)10.8 V

Free

Multiple Choice

Q 51Q 51

An ac generator producing 10 V (rms)at 200 rad/s is connected in series with a 50- resistor, a 400-mH inductor, and a 200-F capacitor.The rms voltage across the inductor is:
A)2.5 V
B)3.4 V
C)6.7 V
D)10.0 V
E)10.8 V

Free

Multiple Choice

Q 52Q 52

An RL series circuit is connected to an ac generator with a maximum emf of 20 V.If the maximum potential difference across the resistor is 16 V, then the maximum potential difference across the inductor is:
A)2 V
B)4 V
C)12 V
D)26 V
E)36 V

Free

Multiple Choice

Q 53Q 53

In an RLC series circuit, which is connected to a source of emf

_{m}cos(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/CFree

Multiple Choice

Q 54Q 54

An RLC series circuit has L = 100 mH and C = 1 F.It is connected to a 1000-Hz source emf, and the voltage is found to lead the current by 75.The value of R is:
A)12.6
B)126
C)175
D)1750
E)1810

Free

Multiple Choice

Q 55Q 55

An RLC series circuit is connected to an oscillator with a maximum emf of 100 V.If the voltage amplitudes V

_{R}, V_{L}, and V_{C}are all equal to each other, then V_{R}must be: A)33 V B)50 V C)67 V D)87 V E)100 VFree

Multiple Choice

Q 56Q 56

An ac generator produces 10 V (rms)at 400 rad/s.It is connected to a series RL circuit (R = 17.3 , L = 0.025 H).The rms current is:
A)0.50 A and leads the emf by 30
B)0.71 A and lags the emf by 30
C)1.4 A and lags the emf by 60
D)0.50 A and lags the emf by 30
E)0.58 A and leads the emf by 90

Free

Multiple Choice

Q 57Q 57

In a purely capacitive circuit the current:
A)leads the voltage by one-fourth of a cycle
B)leads the voltage by one-half of a cycle
C)lags the voltage by one-fourth of a cycle
D)lags the voltage by one-half of a cycle
E)is in phase with the potential difference across the plates

Free

Multiple Choice

Q 58Q 58

In a purely resistive circuit the current:
A)leads the voltage by 1/4 cycle
B)leads the voltage by 1/2 cycle
C)lags the voltage by 1/4 cycle
D)lags the voltage by 1/2 cycle
E)is in phase with the voltage

Free

Multiple Choice

Q 59Q 59

In a purely inductive circuit, the current lags the voltage by:
A)0 (they are in phase)
B)one-fourth of a cycle
C)one-half of a cycle
D)three-fourths of a cycle
E)one cycle

Free

Multiple Choice

Q 60Q 60

A series RL circuit is connected to an emf source of angular frequency .The current:
A)leads the applied emf by tan

^{-1}(L/R) B)lags the applied emf by tan^{-1}(L/R) C)lags the applied emf by tan^{-1}(R/L) D)leads the applied emf by tan^{-1}(R/L) E)is zeroFree

Multiple Choice

Q 61Q 61

An RC series circuit is connected to an emf source having angular frequency .The current:
A)leads the source emf by tan

^{-1}(1/CR) B)lags the source emf by tan^{-1}(1/CR) C)leads the source emf by tan^{-1}(CR) D)lags the source emf by tan^{-1}(CR) E)leads the source emf by /4Free

Multiple Choice

Q 62Q 62

An RLC series circuit is driven by a sinusoidal emf with angular frequency

_{d}.If _{d}is increased without changing the amplitude of the emf, the current amplitude increases.If L is the inductance, C is the capacitance, and R is the resistance, this means that: A)_{d}L > 1/_{d}C B)_{d}L < 1/_{d}C C)_{d}L = 1/_{d}C D)_{d}L > R E)_{d}L < RFree

Multiple Choice

Q 63Q 63

In a sinusoidally driven series RLC circuit, the inductive resistance is X

_{L}= 200 , the capacitive reactance is X_{C}= 100 , and the resistance is R = 50 .The current and applied emf would be in phase if: A)the resistance is increased to 100 , with no other changes B)the resistance is increased to 200 , with no other changes C)the inductance is reduced to zero, with no other changes D)the capacitance is doubled, with no other changes E)the capacitance is halved, with no other changesFree

Multiple Choice

Q 64Q 64

An RLC series circuit, connected to a source , is at resonance.Then:
A)the voltage across R is zero
B)the voltage across R equals the applied voltage
C)the voltage across C is zero
D)the voltage across L equals the applied voltage
E)the applied voltage and current differ in phase by 90

Free

Multiple Choice

Q 65Q 65

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

Free

Multiple Choice

Free

Multiple Choice

Q 67Q 67

A sinusoidal voltage V(t)has an rms value of 100 V.Its maximum value is:
A)70.7 V
B)100 V
C)141 V
D)200 V
E)707 V

Free

Multiple Choice

Q 68Q 68

In a series RLC circuit the rms value of the generator emf is and the rms value of the current is i.The current lags the emf by .The average power supplied by the generator is given by:
A)(i/2)cos
B)i
C)i

^{2}/Z D)i^{2}Z E)i^{2}RFree

Multiple Choice

Q 69Q 69

In a sinusoidally driven series RLC circuit the current lags the applied emf.The rate at which energy is dissipated in the resistor can be increased by:
A)decreasing the capacitance and making no other changes
B)increasing the capacitance and making no other changes
C)increasing the inductance and making no other changes
D)increasing the driving frequency and making no other changes
E)decreasing the amplitude of the driving emf and making no other changes

Free

Multiple Choice

Q 70Q 70

An RLC circuit has a sinusoidal source of emf.The average rate at which the source supplies energy is 5 nW.This must also be:
A)the average rate at which energy is stored in the capacitor
B)the average rate at which energy is stored in the inductor
C)the average rate at which energy is dissipated in the resistor
D)twice the average rate at which energy is stored in the capacitor
E)three times the average rate at which energy is stored in the inductor

Free

Multiple Choice

Q 71Q 71

The rms value of an ac current is:
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

Free

Multiple Choice

Q 72Q 72

The average power supplied to the circuit shown passes through a maximum when which one of the following is increased continuously from a very low to a very high value?
A)source emf
B)R
C)C
D)source frequency f
E)none of these

Free

Multiple Choice

Q 73Q 73

A series circuit consists of a 15- resistor, a 25-mH inductor, and a 35-F capacitor.If the frequency is 100 Hz the power factor is:
A)0
B)0.20
C)0.45
D)0.65
E)1.0

Free

Multiple Choice

Q 74Q 74

In order to maximize the rate at which energy is supplied to a resistive load, the power factor of an RLC circuit should be as close as possible to:
A)0
B)0.5
C)1
D)infinity
E)cannot tell without knowing R, L, C, and the driving frequency

Free

Multiple Choice

Q 75Q 75

The main reason that alternating current replaced direct current for general use is:
A)ac generators do not need slip rings
B)ac voltages may be conveniently transformed
C)electric clocks do not work on dc
D)a given ac current does not heat a power line as much as the same dc current
E)ac minimizes magnetic effects

Free

Multiple Choice

Q 76Q 76

Iron, rather than copper, is used in the core of transformers because iron:
A)can withstand a higher temperature
B)has a greater resistivity
C)has a very high permeability
D)makes a good permanent magnet
E)insulates the primary from the secondary

Free

Multiple Choice

Q 77Q 77

The core of a transformer is made in a laminated form to:
A)facilitate easy assembly
B)reduce i

^{2}R losses in the coils C)increase the magnetic flux D)save weight E)prevent eddy currentsFree

Multiple Choice

Q 78Q 78

For a power transmission line, the transmission should be at low current and high voltage because:
A)this is the least dangerous to electrical workers
B)this gives the least dose of electromagnetic radiation to the public
C)this minimizes transmission losses
D)low current and high voltage is easier to transform than high current and low voltage
E)household appliances run at low current and high voltage

Free

Multiple Choice

Q 79Q 79

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

Free

Multiple Choice

Q 80Q 80

A generator supplies 100 V to the primary coil of a transformer.The primary has 50 turns and the secondary has 500 turns.The secondary voltage is:
A)1000 V
B)500 V
C)250 V
D)100 V
E)10 V

Free

Multiple Choice

Q 81Q 81

A step-down transformer is used to:
A)increase the power
B)decrease the power
C)increase the voltage
D)decrease the voltage
E)change ac to dc

Free

Multiple Choice

Q 82Q 82

The resistance of the primary coil of a well-designed, 1:10 step-down transformer is 1 .With the secondary circuit open, the primary is connected to a 12 V ac generator.The primary current is:
A)essentially zero
B)about 12 A
C)about 120 A
D)depends on the actual number of turns in the primary coil
E)depends on the core material

Free

Multiple Choice

Q 83Q 83

The primary of an ideal transformer has 100 turns and the secondary has 600 turns.Then:
A)the power in the primary circuit is less than that in the secondary circuit
B)the currents in the two circuits are the same
C)the voltages in the two circuits are the same
D)the primary current is six times the secondary current
E)the frequency in the secondary circuit is six times that in the primary circuit

Free

Multiple Choice

Q 84Q 84

The primary of a 3:1 step-up transformer is connected to a source and the secondary is connected to a resistor R.The power dissipated by R in this situation is P.If R is connected directly to the source it will dissipate a power of:
A)P/9
B)P/3
C)P
D)3P
E)9P

Free

Multiple Choice

Q 85Q 85

In an ideal 1:8 step-down transformer, the primary power is 10 kW and the secondary current is 25 A.The primary voltage is:
A)25,600 V
B)3200 V
C)400 V
D)50 V
E)6.25 V

Free

Multiple Choice

Q 86Q 86

A source with an impedance of 100 is connected to the primary coil of a transformer and a resistance R is connected to the secondary coil.If the transformer has 500 turns in its primary coil and 100 turns in its secondary coil the greatest power will be dissipated in the resistor if R =
A)0
B)0.25
C)4.0
D)20
E)100

Free

Multiple Choice