Which of the following statements pertains to resistors only?
Which of the following statements pertains to resistors only?
At very low frequencies a series R-C circuit behaves as almost purely
At very low frequencies a series R-C circuit behaves as almost purely
The power factor at resonance in R-L-C parallel circuit is
The power factor at resonance in R-L-C parallel circuit is
In AC. circuits, laminated iron is invariably used in order to
In AC. circuits, laminated iron is invariably used in order to
In a pure capacitive circuit if the supply frequency is reduced to 1/2, the current will
In a pure capacitive circuit if the supply frequency is reduced to 1/2, the current will
In a series resonant circuit, the impedance of the circuit is
In a series resonant circuit, the impedance of the circuit is
Inductance of coil
Inductance of coil
Power factor of electric bulb is
Power factor of electric bulb is
Which of the following refers to a parallel circuit?
Which of the following refers to a parallel circuit?
The purpose of a parallel circuit resonance is to magnify
The purpose of a parallel circuit resonance is to magnify
Pure inductive circuit
Pure inductive circuit
Two waves of the same frequency have opposite phase when the phase angle between them is
Two waves of the same frequency have opposite phase when the phase angle between them is
A parallel AC. circuit in resonance will
A parallel AC. circuit in resonance will
For a frequency of 200 Hz, the time period will be
For a frequency of 200 Hz, the time period will be
The inductance of a coil can be increased by
The inductance of a coil can be increased by
The double energy transient occur in the
The double energy transient occur in the
Which of the following circuit component opposes the change in the circuit voltage ?
Which of the following circuit component opposes the change in the circuit voltage ?
Capacitive reactance is more when
Capacitive reactance is more when
The r.m.s. value of half wave rectified sine wave is 200 V. The r.m.s. value of full wave rectified AC. will be
The r.m.s. value of half wave rectified sine wave is 200 V. The r.m.s. value of full wave rectified AC. will be
Form Factor is the ratio of
Form Factor is the ratio of
Inductance of a coil Varies
Inductance of a coil Varies
The best place to install a capacitor is
The best place to install a capacitor is
If two sinusoids of the same frequency but of different amplitudes and phase angles are subtracted, the resultant is
If two sinusoids of the same frequency but of different amplitudes and phase angles are subtracted, the resultant is
In the case of an unsymmetrical alternating current the average value must always be taken over
In the case of an unsymmetrical alternating current the average value must always be taken over
A pure capacitor connected across an A.C. voltage consumed 50 W. This is due to
A pure capacitor connected across an A.C. voltage consumed 50 W. This is due to
In a R-L-C circuit
In a R-L-C circuit
For the same peak value, which of the following wave has the least mean value?
For the same peak value, which of the following wave has the least mean value?
Form factor for a sine wave is
Form factor for a sine wave is
Magnitude of current at resonance in R-L-C circuit
Magnitude of current at resonance in R-L-C circuit
The equation of 50 Hz current sine wave having r.m.s. value of 60 A is
The equation of 50 Hz current sine wave having r.m.s. value of 60 A is
The product of apparent power and cosine of the phase angle between circuit voltage and current is
The product of apparent power and cosine of the phase angle between circuit voltage and current is
If two sine waves of the same frequency have a phase difference of JT radians, then
If two sine waves of the same frequency have a phase difference of JT radians, then
If resistance is 20 Q. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be
If resistance is 20 Q. and inductance is 27 in a R-L series circuit, then time constant of this circuit will be
The series and parallel resonance on L-C circuit' differs in that
The series and parallel resonance on L-C circuit' differs in that
Capacitors for power factor correction are rated in
Capacitors for power factor correction are rated in
In a purely inductive circuit
In a purely inductive circuit
In an A.C. circuit power is dissipated in
In an A.C. circuit power is dissipated in
Power factor of the system is kept high
Power factor of the system is kept high
The time constant of a series R-C circuit is given by
The time constant of a series R-C circuit is given by
The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes __________ ohms.
The reactance offered by a capacitor to alternating current of frequency 50 Hz is 20 Q. If frequency is increased to 100 Hz, reactance becomes __________ ohms.
In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters?
In each of the three coils of a three phase generator, an alternating voltage having an r.m.s. value of 220 V is induced. Which of the following values is indicated by the voltmeters?
In a series L-C circuit at the resonant frequency the
In a series L-C circuit at the resonant frequency the
The period of a wave is
The period of a wave is
Poor power factor
Poor power factor
Power factor of the following circuit will be zero
Power factor of the following circuit will be zero
The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA
The power drawn by the circuit is
The input of an A.C. circuit having power factor of 0.8 lagging is 40 kVA
The power drawn by the circuit is
Power factor of an inductive circuit is usually improved by connecting capacitor to it in
Power factor of an inductive circuit is usually improved by connecting capacitor to it in
In any A.C. circuit always
In any A.C. circuit always
In a highly capacitive circuit the
In a highly capacitive circuit the
A pure inductance connected across 250 V, 50 Hz supply consumes 100 W. This consumption can be attributed to
A pure inductance connected across 250 V, 50 Hz supply consumes 100 W. This consumption can be attributed to
The ratio of active power to apparent power is known as factor.
The ratio of active power to apparent power is known as factor.
At __________ frequencies the parallel R-L circuit behaves as purely resistive.
At __________ frequencies the parallel R-L circuit behaves as purely resistive.
In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of
In R-L-C series resonant circuit magnitude of resonance frequency can be changed by changing the value of
The r.m.s. value and mean value is the same in the case of
The r.m.s. value and mean value is the same in the case of
In a loss-free R-L-C circuit the transient current is
In a loss-free R-L-C circuit the transient current is
All the rules and laws of D.C. circuit also apply to A.C. circuit containing
All the rules and laws of D.C. circuit also apply to A.C. circuit containing
The peak value of a sine wave is 200 V. Its average value is
The peak value of a sine wave is 200 V. Its average value is
The square waveform of current has following relation between r.m.s. value and average value.
The square waveform of current has following relation between r.m.s. value and average value.
The safest value of current the human body can carry for more than 3 second is
The safest value of current the human body can carry for more than 3 second is
An A.C. voltage is impressed across a pure resistance of 3.5 ohms in parallel with a pure inductance of impedance of 3.5 ohms,
An A.C. voltage is impressed across a pure resistance of 3.5 ohms in parallel with a pure inductance of impedance of 3.5 ohms,
In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will
In a pure inductive circuit if the supply frequency is reduced to 1/2, the current will
The form factor is the ratio of
The form factor is the ratio of
A sine wave has a frequency of 50 Hz. Its angular frequency is __________ radian/second.
A sine wave has a frequency of 50 Hz. Its angular frequency is __________ radian/second.
The power consumed in a circuit element will be least when the phase difference between the current and voltage is
The power consumed in a circuit element will be least when the phase difference between the current and voltage is
In a pure inductive circuit
In a pure inductive circuit
What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value?
What will be the phase angle between two alternating waves of equal frequency, when one wave attains maximum value the other is at zero value?
Inductance affects the direct current flow
Inductance affects the direct current flow
Which of the following waves has the highest value of peak factor ?
Which of the following waves has the highest value of peak factor ?
Capacitive susceptance is a measure of
Capacitive susceptance is a measure of
The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of ________ degrees.
The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of ________ degrees.
In a pure resistive circuit
In a pure resistive circuit
Time constant of an inductive circuit
Time constant of an inductive circuit
Power factor of the following circuit will be unity
Power factor of the following circuit will be unity
Time constant of a circuit is the time in seconds taken after the application of voltage to each
Time constant of a circuit is the time in seconds taken after the application of voltage to each
For the same peak value which of the following wave will 'have the highest r.m.s. value?
For the same peak value which of the following wave will 'have the highest r.m.s. value?
In a circuit containing R, L and C, power loss can take place in
In a circuit containing R, L and C, power loss can take place in
In a parallel R-C circuit, the current always _________the applied voltage
In a parallel R-C circuit, the current always _________the applied voltage
If a sinusoidal wave has frequency of 50 Hz with 30 A r.m.s. current which of the following equation represents this wave?
If a sinusoidal wave has frequency of 50 Hz with 30 A r.m.s. current which of the following equation represents this wave?
Pure inductive circuit takes power from the A.C. line when
Pure inductive circuit takes power from the A.C. line when
The frequency of an alternating current is
The frequency of an alternating current is
In a sine wave the slope is constant
In a sine wave the slope is constant
Skin effect occurs when a conductor carries current at _________ frequencies.
Skin effect occurs when a conductor carries current at _________ frequencies.
In a three-phase supply floating neutral is undesirable because it way give rise to
In a three-phase supply floating neutral is undesirable because it way give rise to
The power is measured in terms of decibels in case of
The power is measured in terms of decibels in case of
The power factor of a D.C. circuit is always
The power factor of a D.C. circuit is always
The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is
The apparent power drawn by an A.C. circuit is 10 kVA and active power is 8 kW. The reactive power in the circuit is
In an AC. circuit, a low value of kVAR compared with kW indicates
In an AC. circuit, a low value of kVAR compared with kW indicates
Which of the following coil will have large resonant frequency?
Which of the following coil will have large resonant frequency?
A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to
A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to
Wire-wound resistors are unsuitable for use at high frequencies because they
Wire-wound resistors are unsuitable for use at high frequencies because they
For a sine wave with peak value Emax ___________ 8.30. the average value is
For a sine wave with peak value Emax ___________ 8.30. the average value is
All definitions of power factor of a series R-L-C circuit are correct except
All definitions of power factor of a series R-L-C circuit are correct except
The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that
The phase difference between voltage and current wave through a circuit element is given as 30°. The essential condition is that
The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of
The effective resistance of an iron-cored choke working on ordinary supply frequency is more than its true resistance because of
The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces
The r.m.s. value of alternating current is given by steady (D.C.) current which when flowing through a given circuit for a given time produces
The transient currents are associated with the
The transient currents are associated with the
The time constant of the capacitance circuit is defined as the time during which voltage
The time constant of the capacitance circuit is defined as the time during which voltage
In series resonant circuit, increasing inductance to its twice value and reducing capacitance to its half value
In series resonant circuit, increasing inductance to its twice value and reducing capacitance to its half value
The r.m.s. value of pure cosine function is
The r.m.s. value of pure cosine function is
Ohm is unit of all of the following except
Ohm is unit of all of the following except
Time constant of a capacitive circuit
Time constant of a capacitive circuit
Power factor of an electrical circuit is equal to
Power factor of an electrical circuit is equal to
The frequency of domestic power supply in India is
The frequency of domestic power supply in India is
When an alternating current passes through an ohmic resistance the electrical power converted into heat is
When an alternating current passes through an ohmic resistance the electrical power converted into heat is
The phosphors for which of the following pair are 180° out of phase for VL, VC and VR?
The phosphors for which of the following pair are 180° out of phase for VL, VC and VR?
The period of a sine wave is ___________ seconds. Its frequency is
The period of a sine wave is ___________ seconds. Its frequency is
The voltage of domestic supply is 220 V. This figure represents
The voltage of domestic supply is 220 V. This figure represents
For a sine wave with peak value Imax the r.m.s. value is
For a sine wave with peak value Imax the r.m.s. value is
