Description : A transformer has negative voltage regulation when its load power factor is (1) Zero (2) Unity (3) Leading (4) Lagging
Answer :
Leading
asked
Apr 30, 2018
by
anonymous
Description : Minimum voltage regulation occurs when the power factor of the load is?
Answer :
Minimum voltage regulation occurs when the power factor of the load is leading.
asked
Mar 19, 2018
by
anonymous
Description : A good voltage regulation of a transformer means?
Answer :
A good voltage regulation of a transformer means output voltage fluctuation from no load to full load is least.
asked
Mar 19, 2018
by
anonymous
Description : Identify the increasing order of voltage regulation of the following dc generators a same load : (A) differential compound, shunt and under compound (B) shunt, differential compound and under compound (C) under compound, shunt and differential compound (D) shunt, under compound and differential compound
Answer :
Identify the increasing order of voltage regulation of the following dc generators a same load : under compound, shunt and differential compound
asked
Apr 30, 2018
by
anonymous
Description : Define load and line regulation.
Answer :
1. Load regulation : The load regulation indicates how much the load voltage changes when the load current changes. The load regulation is defined as: % Load regulation = (VNL-VFL) / VFL *100 ... the power supply. A well-regulated power supply can have a line regulation of less than 0.1%.
asked
Sep 5, 2018
by
anonymous
Answer :
The voltage regulation in magnetic amplifier type voltage regulator is effected by varying the reactance.
asked
Mar 20, 2018
by
anonymous
Description : An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is (1) 141 (2) 92.3 (3) 9.23 (4) 1.41
Answer :
An amplifier has a voltage gain of 120. To reduce distortion, 10% negative feedback is employed. The gain of the amplifier with feedback is 9.23
asked
May 1, 2018
by
anonymous
Description : In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are?
Answer :
In a given transformer for a given applied voltage, losses which remain constant irrespective of load changes are hysteresis and eddy current losses.
asked
Mar 19, 2018
by
anonymous
Description : An SSB transmitter produces a peak-to-peak voltage of 200 V across a 100 Ω antenna load. What is the Peak Envelope Power? A) 49.98 W B) 79.98 W C) 99.96 W D) 199.93 W
Answer :
An SSB transmitter produces a peak-to-peak voltage of 200 V across a 100 Ω antenna load. What is the Peak Envelope Power? A) 49.98 W B) 79.98 W C) 99.96 W D) 199.93 W
asked
Jun 18, 2018
by
anonymous
Description : A zener voltage regulator has load requirements of 12 V and 2 A. The zener diode minimum current requirement is 0.2 A. The minimum voltage at input is 24 V. What is the required value of series resistance with source? A) 5.45 Ω B) 6 Ω C) 7.2 Ω D) 6.38 Ω
Answer :
A zener voltage regulator has load requirements of 12 V and 2 A. The zener diode minimum current requirement is 0.2 A. The minimum voltage at input is 24 V. What is the required value of series resistance with source? A) 5.45 Ω B) 6 Ω C) 7.2 Ω D) 6.38 Ω
asked
Jun 18, 2018
by
anonymous
Description : A 3-phase voltage source inverter operates in 180° conduction mode with a star connected resistive load. If input dc voltage is 100 V, then the peak to peak output line voltage is :
Answer :
A 3-phase voltage source inverter operates in 180° conduction mode with a star connected resistive load. If input dc voltage is 100 V, then the peak to peak output line voltage is : 200 V
asked
Apr 30, 2018
by
anonymous
Description : A single-phase voltage source square -wave inverter feeds pure inductive load. The waveform of the load current will be
Answer :
A single-phase voltage source square -wave inverter feeds pure inductive load. The waveform of the load current will be triangular
asked
Apr 29, 2018
by
anonymous
Answer :
In a level compounded D.C. generator, full load terminal voltage is equal to no-load terminal voltage.
asked
Mar 21, 2018
by
anonymous
Answer :
In over compounded generator, full load terminal voltage is more than no load terminal voltage.
asked
Mar 21, 2018
by
anonymous
Answer :
A transformer can have regulation closer to zero on leading power factor.
asked
Mar 19, 2018
by
anonymous
Description : A ferro resonant transformer regulation is also known as?
Answer :
A ferro resonant transformer regulation is also known as constant current transformer.
asked
Mar 19, 2018
by
anonymous
Description : Define line regulation and load regulation.
Answer :
Load regulation is the ability of the power supply to maintain its specified output voltage over changes in the load. Line regulation is the ability of the power supply to maintain its specified output voltage over changes in the input line voltage.
asked
Jul 24, 2019
by
anonymous
Description : The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as?
Answer :
The maximum constant load torque under which a synchronous motor will pull into synchronism at rated rotor supply voltage and frequency is known as pull-in torque.
asked
Mar 20, 2018
by
anonymous
Answer :
An ideal transformer will have maximum efficiency at a load such that copper loss equal to iron loss.
asked
Mar 19, 2018
by
anonymous
Description : The maximum load that a power transformer can carry is limited by its?
Answer :
The maximum load that a power transformer can carry is limited by its voltage ratio.
asked
Mar 19, 2018
by
anonymous
Description : Classify hydro-electric power plants according to water flow regulation and explain in brief.
Answer :
Classification of hydro-electric power plants according to water flow regulation of water flow:- 1. Large reservoir power plant 2. Run-off river (ROR) power plant with poundage 3. Run-off River ... depends upon rate of flow of water Initial cost is less Its purpose is to generate electricity.
asked
Sep 7, 2018
by
anonymous
Description : The unit of speed regulation of a governor is : (A) Hz (B) Hz/MW (C) Hz/MVA (D) rpm/MVAR
Answer :
The unit of speed regulation of a governor is : Hz/MW
asked
Apr 29, 2018
by
anonymous
Description : Which motor has the best speed regulation?
asked
Mar 15, 2018
by
anonymous
Description : Compare positive and negative feedback.
Answer :
Sr. No. Parameter Positive feedback Negative feedback 1 BW Increases Decreases 2 Feedback signal In phase with the input signal. 180 º out of phase ... impedance increases decreases 9 Uses Oscillators, Schmitt trigger Amplifiers, bootstrapping
asked
Sep 3, 2019
by
anonymous
Description : Write advantages and disadvantages of positive and negative feedback.
Answer :
Advantages of Positive Feedback: i) Voltage gain increases. ii) No phase shift is provided. iii) Feedback signal and input signal are in phase. iv) Input and Output voltage increases. ... ii) Feedback signal and input signal are out of phase. iii) Input and Output voltage decreases.
asked
Sep 5, 2018
by
anonymous
Description : Differentiate between positive and negative feedback.
Answer :
PARAMETER POSITIVE FEEDBACK NEGATIVE FEEDBACK Overall phase shift 0° or 360° 180° Feedback and input signal Are in phase Are out of phase Input signal ... Increases Input impedance Decreases Increases Output impedance Increases Decreases
asked
Sep 5, 2018
by
anonymous
Description : Define negative and positive feedback
Answer :
1. Negative feedback: Feedback in which feedback signal is out of phase with input signal and it decreases output is called negative feedback. 2. Positive feedback: Feedback in which feedback signal is in phase with input signal and it increases output is called positive feedback.
asked
Sep 5, 2018
by
anonymous
Description : The effect of negative feedback on distortion and bandwidth is A) Both distortion and bandwidth get decreased B) Both distortion and bandwidth get increased C) Distortion is reduced and bandwidth is increased D) Distortion is increased and bandwidth is decreased
Answer :
The effect of negative feedback on distortion and bandwidth is Distortion is reduced and bandwidth is increased
asked
Jun 18, 2018
by
anonymous
Description : A negative sequence relay is used for protection of (1) Generator (3) Motor (2) Transformer (4) Long Transmission lines
Answer :
A negative sequence relay is used for protection of Generator
asked
May 1, 2018
by
anonymous
Description : A unity negative feedback control system is found to have a gain margin of 20 dB. The Nyquist plot of the system (A) crosses the real axis at +0.1 (B) crosses the real axis at -0.1. (C) crosses the imaginary axis at -0.1 (D) crosses the imaginary axis at +0.1
Answer :
A unity negative feedback control system is found to have a gain margin of 20 dB. The Nyquist plot of the system crosses the real axis at -0.1.
asked
Apr 28, 2018
by
anonymous
Description : Which diode exhibits negative resistance characteristic? (A) LED (B) Zener (C) Tunnel diode (D) PN diode
Answer :
Which diode exhibits negative resistance characteristic? (A) LED (B) Zener (C) Tunnel diode (D) PN diode
asked
Apr 28, 2018
by
anonymous
Description : Negative feedback in a closed-loop control system DOES NOT (A) reduce the overall gain (B) reduce bandwidth (C) improve disturbance rejection (D) reduce sensitivity to parameter variation
Answer :
Negative feedback in a closed-loop control system DOES NOT reduce bandwidth
asked
Apr 26, 2018
by
anonymous
Description : The transducer with negative temperature co-efficient of resistance is (A) Thermistor (B) Resistance Thermometer (C) Strain Gauge (D) Thermocouple
Answer :
The transducer with negative temperature co-efficient of resistance is Thermistor
asked
Apr 25, 2018
by
anonymous
Description : Which side of a capacitor is negative?
Answer :
In electrolytic type negative is shorter lead and usually mark in the tank. But of course not applicable to non-polar.
asked
Mar 15, 2018
by
anonymous
Description : Is an anode positive or negative?
Answer :
The anode is positively charged electrode.
asked
Mar 14, 2018
by
anonymous
Description : Why does charge flow from positive to negative?
asked
Mar 14, 2018
by
anonymous
Description : How does negative feedback reduces distortion in an amplifier?
asked
Mar 10, 2018
by
anonymous
Answer :
In an actual transformer the iron loss remains practically constant from no load to full load because core flux remains practically constant.
asked
Mar 19, 2018
by
anonymous
Description : For a transformer, operating at constant load current, maximum efficiency will occur at?
Answer :
For a transformer, operating at constant load current, maximum efficiency will occur at unity power factor.
asked
Mar 19, 2018
by
anonymous
Description : The efficiency of two identical transformers under load conditions can be determined by?
Answer :
The efficiency of two identical transformers under load conditions can be determined by back-to-back test.
asked
Mar 19, 2018
by
anonymous
Description : In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of?
Answer :
In a step-down transformer, there is a change of 15 A in the load current. This results in change of supply current of less than 15A.
asked
Mar 19, 2018
by
anonymous
Description : In a transformer, zero voltage regulation at full load is (a)Not possible (b) Possible at unity power factor load (c) Possible at leading power factor load (d) Possible at lagging power factor load
Answer :
In a transformer, zero voltage regulation at full load is Possible at leading power factor load
asked
May 13, 2018
by
anonymous
Description : For given applied voltage, with the increase in frequency of the applied voltage?
Answer :
For given applied voltage, with the increase in frequency of the applied voltage eddy current loss will remain unchanged.
asked
Mar 19, 2018
by
anonymous
Description : The voltage transformation ratio of a transformer is equal to the ratio of?
Answer :
The voltage transformation ratio of a transformer is equal to the ratio of secondary induced e.m.f. to primary induced e.m.f.
asked
Mar 19, 2018
by
anonymous
Description : If a transformer is switched on to a voltage more than the rated voltage?
Answer :
If a transformer is switched on to a voltage more than the rated voltage its power factor will deteriorate.
asked
Mar 19, 2018
by
anonymous
Answer :
The speed/load characteristics of a universal motor is same as that of D.C. series motor.
asked
Mar 20, 2018
by
anonymous
Description : For a balanced three phase star connected load for which line voltage is 230V and per phase resistance and reactance is 6 Ohm and 8 Ohm respectively. Calculate: 1) phase voltage 2) line current 3) power factor 4) total power absorbed
asked
Aug 12, 2018
by
anonymous
Description : In a battery, the difference between the no-load voltage and the measured voltage output is called ________ A) Internal voltage B) Internal resistance C) External resistance D) All the above
Answer :
In a battery, the difference between the no-load voltage and the measured voltage output is called Internal resistance
asked
Apr 29, 2018
by
anonymous
Description : A d.c. source has an open circuit voltage of 30 V and an internal resistance of 1.5 Ohm. A resistive load is connected to the source. Maximum power dissipated in the load is (A) 300 W (B) 150 W (C) 45 W (D) 20 W
Answer :
A d.c. source has an open circuit voltage of 30 V and an internal resistance of 1.5 Ohm. A resistive load is connected to the source. Maximum power dissipated in the load is 150 W
asked
Apr 25, 2018
by
anonymous
Description : A network that consists of at least a voltage source or current source is called A) Active network B) Ideal network C) Sourced network D) Outsourced network
Answer :
A network that consists of at least a voltage source or current source is called Active network
asked
Apr 29, 2018
by
anonymous