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Questions and Answers
The distance that an Alternating Current (A.C.) travels in time period "T" is called:
The distance that an Alternating Current (A.C.) travels in time period "T" is called:
A transformer has 100 turns in the primary coil and 25 turns in the secondary coil. When a 120 V is applied to the primary coil, what is the voltage in the secondary coil?
A transformer has 100 turns in the primary coil and 25 turns in the secondary coil. When a 120 V is applied to the primary coil, what is the voltage in the secondary coil?
In a series LRC circuit, if the capacitive reactance is equal to the inductive reactance, what is the phase angle between current and voltage?
In a series LRC circuit, if the capacitive reactance is equal to the inductive reactance, what is the phase angle between current and voltage?
The magnetic material for the core needs to be made of soft iron where its permeability is high:
The magnetic material for the core needs to be made of soft iron where its permeability is high:
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The other name for the Shaded-Pole Motor is:
The other name for the Shaded-Pole Motor is:
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Thin laminated sheets of Iron are used instead of solid block to:
Thin laminated sheets of Iron are used instead of solid block to:
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Which filters are commonly used because of their compact design and lower price:
Which filters are commonly used because of their compact design and lower price:
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What is impedance?
What is impedance?
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What happens at resonance?
What happens at resonance?
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Which of the following does not change in a transformer?
Which of the following does not change in a transformer?
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Synchronous Machine having 4 poles and supplied with 60 Hz supply will rotate at:
Synchronous Machine having 4 poles and supplied with 60 Hz supply will rotate at:
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In an RLC circuit, power loss can take place in:
In an RLC circuit, power loss can take place in:
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Regarding the relationship between frequency (f) and effective resistance (R):
Regarding the relationship between frequency (f) and effective resistance (R):
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Calculate voltage in the secondary coil based on the information given below. Vp = 240 VNp = 20Ns = 125Vs?
Calculate voltage in the secondary coil based on the information given below. Vp = 240 VNp = 20Ns = 125Vs?
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Which filters are used in smoothing circuits to cancel out the unintended AC parts in a rectifier:
Which filters are used in smoothing circuits to cancel out the unintended AC parts in a rectifier:
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At resonance condition in a RLC series circuit, the impedance will be
At resonance condition in a RLC series circuit, the impedance will be
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What is the phase angle between the voltages of the inductor and capacitor in a RLC series circuit?
What is the phase angle between the voltages of the inductor and capacitor in a RLC series circuit?
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What is the Peak voltage of the signal shown on the multimeter?
What is the Peak voltage of the signal shown on the multimeter?
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Assume primary has 240 turns and secondary has 60 turns. Primary is connected with 120V AC power supply. What is the voltage on the secondary?
Assume primary has 240 turns and secondary has 60 turns. Primary is connected with 120V AC power supply. What is the voltage on the secondary?
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According to Faraday's Law of Induction, the induced voltage in a coil is proportional to?
According to Faraday's Law of Induction, the induced voltage in a coil is proportional to?
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Why is a centrifugal switch used in a 1-ph induction motor?
Why is a centrifugal switch used in a 1-ph induction motor?
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The Turns Ratio in a Transformer is calculated by the formula:
The Turns Ratio in a Transformer is calculated by the formula:
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Which of the following statements about a series RCL circuit is true?
Which of the following statements about a series RCL circuit is true?
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In a shaded pole motor, shading coils are using to
In a shaded pole motor, shading coils are using to
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In large synchronous machine, field winding is placed on
In large synchronous machine, field winding is placed on
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The repetition of a variable quantity, recurring at equal intervals, is known as
The repetition of a variable quantity, recurring at equal intervals, is known as
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The sum of resistance and reactance is referred to as
The sum of resistance and reactance is referred to as
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What is the unit for capacitative reactance?
What is the unit for capacitative reactance?
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An inductor consisting of ohmic resistance and inductive reactance is applied to 115 V AC. Its current is 1 A. What is the impedance?
An inductor consisting of ohmic resistance and inductive reactance is applied to 115 V AC. Its current is 1 A. What is the impedance?
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The filters which let all frequencies pass, apart from a particular frequency band (channel) is called:
The filters which let all frequencies pass, apart from a particular frequency band (channel) is called:
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When a particular inductor is connected to a source of sinusoidal varying voltage with constant amplitude and a frequency of 60.0 Hz, the rms current is 3.0 A. What is the rms current if the source frequency is doubled?
When a particular inductor is connected to a source of sinusoidal varying voltage with constant amplitude and a frequency of 60.0 Hz, the rms current is 3.0 A. What is the rms current if the source frequency is doubled?
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A resistor is connected to an AC power supply. On this circuit, the current...
A resistor is connected to an AC power supply. On this circuit, the current...
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In the given figure, which coil will have maximum induced voltage
In the given figure, which coil will have maximum induced voltage
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The value of a given waveform at any instant time is termed as
The value of a given waveform at any instant time is termed as
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Which one of the below AC parameters shows the effective DC value?
Which one of the below AC parameters shows the effective DC value?
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The total resistance of a circuit with resistance, capacitive reactance and inductive reactance is referred to as:
The total resistance of a circuit with resistance, capacitive reactance and inductive reactance is referred to as:
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A low pass filter is
A low pass filter is
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The magnetic field produced by an alternating current can be thought of as a ..... field.
The magnetic field produced by an alternating current can be thought of as a ..... field.
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Which of the graphs below shows the characteristics for the circuit shown?
Which of the graphs below shows the characteristics for the circuit shown?
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What kind of filter is shown in the figure?
What kind of filter is shown in the figure?
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This phasor diagram for:
This phasor diagram for:
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Calculate potential difference in the secondary coil based on the information given below. Vp = 240 VNp = 20Ns = 125Vs?
Calculate potential difference in the secondary coil based on the information given below. Vp = 240 VNp = 20Ns = 125Vs?
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The maximum instantaneous value measured from zero value is known as?
The maximum instantaneous value measured from zero value is known as?
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If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is:
If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is:
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A coil with an inductance of 10 H is applied to an AC voltage of U = 230, f=50 Hz. Calculate the inductive reactance. (Pie value = 3.14)
A coil with an inductance of 10 H is applied to an AC voltage of U = 230, f=50 Hz. Calculate the inductive reactance. (Pie value = 3.14)
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A capacitor with a capacitive reactance of 800 ohms is applied to an AC voltage U = 400 V. What is the current?
A capacitor with a capacitive reactance of 800 ohms is applied to an AC voltage U = 400 V. What is the current?
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Which of the following statements about capacitive reactance is true?
Which of the following statements about capacitive reactance is true?
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A pure inductor is connected to an AC power supply. In this circuit, the current...
A pure inductor is connected to an AC power supply. In this circuit, the current...
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The Parallel Resonant Circuit blocks certain frequency and therefore is known as:
The Parallel Resonant Circuit blocks certain frequency and therefore is known as:
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Find out the low pass filter from the given frequency response characteristics.
Find out the low pass filter from the given frequency response characteristics.
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Laminated insulation is normally used in the transformer:
Laminated insulation is normally used in the transformer:
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The following impedance circuit shows the characteristics of a
The following impedance circuit shows the characteristics of a
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Study Notes
Summary
- Remarkable win, keep it up!
- 1660 coins
- 47,150 Score
- 2,940 Coins
- 60% Accuracy
- 89 Correct answers
- 58 Incorrect answers
- 2 Partially correct answers
Review Questions
- Question 1: The distance an alternating current (AC) travels in time period "T" is called wavelength.
- Question 2: A transformer has 100 turns in the primary coil and 25 turns in the secondary coil. When 120V is applied to the primary coil, the voltage in the secondary coil is 30V.
- Question 4: The supply given to the rotor winding of a 3-phase induction motor is AC.
- Question 5: In a series LRC circuit, if capacitive reactance equals inductive reactance, the phase angle between current and voltage is 90°.
Other Questions
- Question 6: Magnetic material for the core needs to be soft iron for high permeability to reduce eddy current loss and hysteresis loss.
- Question 7: Another name for a shaded-pole motor is a split-pole motor.
- Question 8: Thin laminated sheets of iron are used instead of a solid block to reduce eddy current effect.
- Question 12: Electrical symbol of a transformer is shown.
- Question 15: Impedance is the vector sum of resistance and total reactance.
- Question 16: At resonance, impedance is maximum.
- Question 17: Current does not change in a transformer.
- Question 18: A synchronous machine with 4 poles and a 60 Hz supply rotates at 1500 rpm.
- Question 19: In an RLC circuit, power loss can occur in Resistance (R), Inductor (L), and Capacitor (C).
- Question 21: Regarding the relationship between frequency (f) and effective resistance (R), R is directly proportional.
- Question 23: Calculating transformer voltage: Vp = 240v, Np = 20, Ns = 125, Vs. =1500V.
- Question 24: Low-pass filters are used in smoothing circuits to remove unintended AC parts in a rectifier.
- Question 25 : Impedance is minimum at resonance in an RLC series circuit.
- Question 26: Phase angle between inductor and capacitor voltages in an RLC series circuit is 180 degrees.
- Question 27: Peak voltage of a signal on a multimeter is shown.
- Question 30: Voltage on the secondary is 30V.
- Question 33: Induced voltage in a coil is proportional to the rate of change of magnetic flux.
- Question 37: Centrifugal switch in a single-phase induction motor is used to improve starting performance and cut off starting winding.
- Question 41: Turns ratio in a transformer is calculated by N1/N2.
- Question 44: At resonance in RLC circuit, total reactance and resistance are equal. The current flowing is maximum.
- Question 45: Shading coils in a shaded-pole motor are used to produce a rotating magnetic field.
- Question 46: Field winding in a large synchronous machine is placed on the rotor.
- Question 47: Repetition of a variable quantity at equal intervals is called a cycle.
- Question 53: The sum of resistance and reactance is called Impedance.
- Question 54: Units of capacitive reactance is Ohms.
- Question 55: Impedance is 115 Ohms.
- Question 56: Filters that let all frequencies pass except for a particular frequency band are called Band-Stop Filters.
- Question 57: Rms current if the frequency is doubled is 6.0 A.
- Question 60: Power factor in an AC circuit is calculated as real power / apparent power
- Question 62: Inductive reactance: XL = 2πfL
- Question 69: Total resistance of a circuit with resistance, capacitive reactance and inductive reactance is impedance
- Question 70: Low-pass filter passes frequencies below the cutoff frequency.
- Question 71: The magnetic field produced by an AC current is a dynamic magnetic field.
- Question 77: Graph showing characteristics of a series circuit is shown.
- Question 78: Filter shown in the figure is a low pass filter.
- Question 88: AC generator and transformer power is measured in Volt-Ampere (VA)
- Question 91: Impedance is calculated with R, XL and XC
- Question 92: Transformers work with AC current because AC produces a changing magnetic field.
- Question 93: Copper losses in a transformer are also known as variable loss
- Question 94: If an electric bulb is connected to an AC source, the voltage and current are in phase.
- Question 97: Electromagnetic Induction is the process of inducing an emf with a change in magnetic flux.
- Question 98: At the same voltage level, a higher frequency results in smaller components.
- Question 99: A transformer with a higher secondary voltage than the primary voltage is considered a step-up transformer.
- Question 100: Phase angle between capacitive voltage and inductive voltage in a series circuit is 180 degrees
- Question 101: Duration of one cycle is called period.
- Question 102: Average power dissipated in an ideal inductor is 0.
- Question 104: Graph reflects apparent power.
- Question 105: Step up transformer ratio is greater than 1.
- Question 106: Transformer reducing voltage is called a step-down transformer
- Question 107: RMS value of sine wave with peak value of 354 V is 250 V.
- Question 113: Maximum instantaneous value is peak value.
- **Question 115:**Secondary power of an ideal transformer with 2:1 voltage ratio and 100 W primary power is 50 W.
- Question 117: Current in an AC resistor circuit is in phase with the voltage.
- Question 121: Current lags the voltage by 90° in an inductor circuit.
- Question 122: If the frequency doubled, the capacitive reactance is half the original value.
- Question 124: Self-induced voltage in a coil is called back emf.
- Question 125: A single-phase induction motor is a self-starting motor.
- Question 129: if applied voltage is 400 V and capacitive reactance is 800 ohms, current is 0.5A.
- Question 132: Copper loss sum of hysteresis and eddy current losses are constant loss.
- Question 134: Average value of alternating current in a full sinusoidal cycle is zero.
- Question 136: A filter significantly attenuating frequencies below a cutoff frequency and passing above it is a high-pass filter.
- Question 137: Alternating current is an electric current whose direction and magnitude change periodically.
- Question 138: Lenz's law states that the direction of an induced current is always such as to oppose the change that produced it.
- Question 140: If frequency of AC increases, the inductive reactance increases, which leads to more opposition to the current flow.
- Question 141: Reactance.
- Question 142: Alternating voltage is represented by V(t) = Vm sin(wt).
- Question 143: The capacitor in the capacitor start induction run ac motor is connected in series with starting winding.
- Question 144: RMS value is the effective DC value of alternating current
- Question 145: At 30 HZ, voltage leads current because XC (capacitive) is less than XL (inductive)
- Question 146: A capacitor blocks DC current.
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Description
Test your knowledge on key concepts in electrical engineering with this quiz. Questions cover topics such as alternating current, transformers, induction motors, and circuit reactance. Challenge yourself to see how well you understand these fundamental principles!
