8 views
in Electrical Engineering by
For an SCR with turn-on time of 5 microsecond, an ideal trigger pulse should have 

 (a) short rise time with pulse width = 3 µsec (b) long rise time with pulse width = 6 µsec (c) short rise time with pulse width = 6 µsec (d) None of the above 

Related questions

1 answer 12 views

Turn-on time of an SCR in series with RL circuit can be reduced by   (a) Increasing circuit resistance R (b) Decreasing R (c) Increasing circuit inductance L (d) Decreasing L 

asked May 13, 2018 in Power Electronics by Shimroz123
0 answers 16 views

Output of an op-amp is a square wave of 4 V peak to peak with a rise time of 5 microsecond and fall time of 4 microsecond.Maximum frequency (in kHz)of undistorted sine wave output of 2 V peak to peak is about  A) 100 B) 150 C) 200 D) 250

asked Apr 9, 2018 in Electronics Engineering by Shimroz123
1 answer 14 views

Turn on time of an SCR can be reduced by using a:

asked May 22, 2018 in Power Electronics by Shimroz123
1 answer 24 views

Circuit turn-off time of an SCR is defined as the time  (A) taken by the SCR turn to be off (B) required for the SCR current to become zero (C) for which the SCR is reverse biased by the commutation circuit (D) for which the SCR is reverse biased to reduce its current below the holding current

asked May 18, 2018 in Power Electronics by Shimroz123
1 answer 33 views

In a 3-phase converter circuit during commutation when one SCR in one phase is turned on to turn-off an SCR in another phase, results in (A) voltage notching (B) harmonic distortion (C) voltage sag (D) voltage swell

asked Apr 28, 2018 in Electronics Engineering by Shimroz123
1 answer 14 views

An ideal voltage source should have?

asked Mar 25, 2018 in Network Analysis by Shimroz123
1 answer 20 views

Turn-on of a thyristor (SCR) takes place when  A) Anode to cathode voltage is positive B) Anode to cathode voltage is negative C) Positive current is applied to gate D) Anode to cathode voltage is positive and positive current pulse is applied to gate

asked May 20, 2018 in Power Electronics by Shimroz123
0 answers 124 views

A digital board has a unipolar square clock of 250MHz. If the clock on the board at all places should have all the harmonic components which have more than 10 % of DC value, the board has to be designed for at least —  A) 250MHz B) 750MHz C) 1250 MHz D) 2500 MHz

asked Apr 9, 2018 in Electrical Engineering by Shimroz123
1 answer 14 views

For a pulse transformer, the material used for its core and the possible turn ration from primary to secondary are respectively   (A) ferrite : 20 : 1 (B) laminated iron : 1 :1 (C) ferrite : 1 : 1 (D) powered iron : 1: 1

asked May 17, 2018 in Transformer by Shimroz123
1 answer 86 views

The clock frequency of an 8085 microprocessor based system is 3 MHz. What should be the minimum pulse width of the INTR signal so that it is recognized successfully? A) 5.6 µs B) 5.7 µs C) 5.8 µs D) 5.9 µs

asked Jun 18, 2018 in Microprocessors and Microcontrollers by Shimroz123
1 answer 17 views

To turn a UJT ON, the forward bias on emitter diode should be:  1. more than the peak point voltage 2. less than the peak point voltage 3. Equal to the peak point voltage 4. Equal to the stand - off voltage  

asked May 13, 2018 in Power Electronics by Shimroz123
0 answers 30 views

Each time you turn on your computer, it will check on the control file  (1) Command.com, io.sys (2) Command.com, date.com, dir.com (3) Command.com, io.sys, msdos.sys (4) Chkdsk.exe 

asked Apr 11, 2018 in Computer Engineering by Shimroz123
0 answers 14 views

Each time you turn the power switch on which control files the computer will check  (1) command.com, io.sys (2) command.com, date.com, time.com (3) command.com, io.sys, msdos.sys (4) chkdsk.exe

asked Apr 10, 2018 in Computer Engineering by Shimroz123
0 answers 16 views

When cathode is positive with respect to anode in an SCR, the number of blocked p-n junctions is   (a) 1 (b) 2 (c) 3 (d) 4 

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
1 answer 17 views

The turn-off time of a thyristor is 30 is at 50°C. What is its turn-off time at 100°C ?

asked Apr 25, 2018 in Electrical Engineering by Shimroz123
1 answer 16 views

The materials used for permanent magnets should have

asked May 24, 2018 in Electrical Engineering by Shimroz123
1 answer 20 views

A material for good magnetic memory should have?

asked Mar 25, 2018 in Electrical Engineering by Shimroz123
1 answer 7 views

A pulse waveform has a high time of 8 ms and a pulse width of 32 ms. The duty - cycle is equal to: A. 25% B. 50% C. 1% D. 100%

asked Apr 12, 2018 in Electrical Engineering by Shimroz123
0 answers 55 views

For an SCR, dV/dt protection is achieved by the use of   (a) RL in series with SCR (b) L in series with SCR (c) RC in series with SCR (d) RC across SCR

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
0 answers 59 views

A Lissajous pattern on an oscilloscope has 5 horizontal tangencies and 2 vertical tangencies. The frequency of the horizontal input is 1000 Hz. What is the frequency of the vertical input?  (A) 400 Hz (B) 5000 Hz (C) 4000 Hz (D) 2500 Hz

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
0 answers 16 views

A commutator with a diameter of 50 cm rotates at 1000 r.p.m. If brush width is 1.5 cm, the time of commutation will be (a) 0.168 m sec (b) 0.374 m sec (c) 0.481 m sec (d) 0.573 m sec

asked May 25, 2018 in Electrical Machine by Shimroz123
0 answers 142 views

The hysteresis loop of magnetic material has an area of 5 cm2 with the scales given as 1 cm=2AT and 1 cm=50 mWb, at 50 Hz, the total hysteresis loss is  (A) 15 W (B) 20 W (C) 25 W (D) 50 W 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 10 views

Consider the following statements : Any element connected in  1. Series with an ideal current source is redundant. 2. Parallel with an ideal current source is redundant. 3. Series with an ideal voltage source is redundant. . 4. Parallel with an ideal voltage source is redundant.  Which of the above statements is/are correct ?

asked Apr 23, 2018 in Electrical Engineering by Zeeshan
1 answer 25 views

 Which one of the following does not have an effect on corona ?  (a) Spacing between conductors (b) Conductor size (c) Line voltage (d) Length of conductor

asked Apr 25, 2018 in Electrical Engineering by Shimroz123
1 answer 74 views

Give broad classification of maintenance with meaning of each type. State the factors on which ideal maintenance of electric rolling stock is judged. Give any two means to improve any one factor of these.

asked Sep 2, 2018 by Shimroz123
1 answer 34 views

For a traction transformer circuit breaker state: 1) Rated current and rupturing capacity 2) Any two tests it should be capable of withstanding 3) Overall tripping time and relay time.

asked Sep 2, 2018 by Shimroz123
0 answers 21 views

A dc shunt motor runs at 500 r.p.m at 220 V. A resistance of 4.5 Ω is added in series with the armature for speed control. The armature resistance is 0.5 ohms. The current to stall the motor will be (1) 44 A (2) 50 A (3) 44.4 A (4) 60 A  

asked Apr 11, 2018 in Electrical Engineering by Shimroz123
1 answer 12 views

A resistor with the color coded value of 1000 ohms and ± 10% tolerance can have an actual resistance between ________. A. 990 ohm and 1010 ohm B. 900 ohm and 1100 ohm C. 1000 ohm and 1100 ohm D. 900 ohm and 1000 ohm. 

asked Apr 12, 2018 in Electrical Engineering by Shimroz123
0 answers 18 views

What is the clock cycle time for a system that uses a clock with frequency of 150 kHz?  (A) 55 µ sec (B) 5.5 µ sec (C) 202 sec (D) 6.6 µ sec 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 112 views

The time/div and voltage/div axes of an oscilloscope have been erased. When a 1 kHz, 5V p-p square wave calibration pulse is connected to channel 1 ofthe scope the waveform observed on the screen is as shown in the upper trace of the figure. An unknown signal is connected to channel 2 (lower trace) ofthe scope. If the time/div and V/div on both channels are the same, the amplitude (pp) and period of the unknown signal are respectively.

asked May 20, 2018 in Electrical Measurements and Instrumentation by Shimroz123
1 answer 22 views

What is the charge on each capacitor when a 150 V is applied across two capacitors with values 5 μF and 10 μF, connected in series? A) 500 μC B) 0.5 μC C) 0.5 C D) None of these

asked Apr 29, 2018 in Electrical Engineering by Shimroz123
0 answers 18 views

A coherent QPSK demodulator is required on ground for receiving data from a LEO satellite. What should be optimum order of PLL in the carrier phase tracking loop?  A) 1st order B) 2nd order C) 3rd order D) None of the above

asked Apr 9, 2018 in Electrical Engineering by Shimroz123
0 answers 58 views

To enable dc series motor work satisfactory with an AC supply, the following modifications should be done (1) The yoke and poles should be completely laminated (2) The poles should be made of laminated steel (3) The air gap between stator and rotor be reduced (4) Compensating poles should be introduced  

asked Apr 11, 2018 in Electrical Engineering by Shimroz123
1 answer 13 views

Consider the following statements with regard to a GTO : 1. The turn-off gain of the GTO is large. 2. Large negative gate current pulses are required to turn off the GTO. 3. GTO has large reverse blocking capability. Which of the above statements is/are correct ? (a) 1 only (b) 2 only (c) 3 only (d) 1, 2 and 3

asked Apr 25, 2018 in Electrical Engineering by Shimroz123
1 answer 24 views

What is the power factor when a single phase watt meter operating on 200 V and 5 A for 5 hours makes 2016 revolutions and the meter constant in revolution is 420? A) 0.04 B) 1.04 C) 0.96 D) None of these

asked Apr 29, 2018 in Electrical Engineering by Shimroz123
1 answer 11 views

One single-phase energy meter operating on 230 V and 5 A for 5 hours makes 1940 revolutions. Meter constant is 400 rev/kWh. The power factor of the load is

asked Apr 23, 2018 in Electrical Engineering by Shimroz123
1 answer 9 views

 To turn a conducting SCR to off state, it is necessary to make : -  a) anode current less than holding current b)gate current zero  c) anode voltage less than break over voltage  d) gate voltage zero

asked Apr 10, 2018 in Instrumentation and control by Shimroz123
0 answers 21 views

A ramp voltage V(t)=100 V is applied to an RC differentiating circuit with R=5 kΩ and C=4 μF. The maximum output voltage is  (A) 0.2 V (B) 2 V (C) 10 V (D) 50 V

asked Apr 5, 2018 in Electrical Engineering by Shimroz123

Welcome to electronics2electrical.com here you can ask questions related to electrical, electronics, mechanical, telecommunication, instrumentation, computer, mathematics, physics etc.
Be respectful to all the members. Do not copy and paste the answers from other websites which have copyright content. While asking question give full details about it.

Categories

Most popular tags

power motor dc circuit transformer voltage current used system phase resistance factor synchronous load ac energy induction electric generator series frequency between speed capacitor use electrical meter line difference control type mosfet transmission magnetic plant high single instrument bjt unit source advantages function diode and machine winding field define torque parallel amplifier supply shunt thyristor motors electricity arduino maximum time relay armature problem value on transformers types coil diagram state flow ratio material three formula starting direction theorem method emf operating efficiency digital wave microprocessor test instruments inductance loss measure operation connected signal low applications effect single-phase network temperature working constant losses different law wattmeter measuring compare controlled breaker drive device logic rc full switch flux wire resistivity disadvantages free of materials machines angle force converter conductor transistor gain open protection scr core measurement number bridge principle generators reactance circuits negative the friction iron loop short pole battery conservation steam resistors hysteresis computer using analog lines secondary station gate a rectifier inverter linear induced relays nuclear capacitance basic characteristics design direct work rotor electronics ammeter forces diesel damping rlc connection factors capacitors minimum insulation moving regulation running self systems air fault range main stability quality starter igbt eddy alternator ideal rl average 3-phase plants arc thermal error fuzzy biasing dielectric pressure balanced superposition errors copper rotation feedback impedance measured electronic electrons charge inductive transfer explain start off back curve over solar is three-phase tariff locomotive peak bias zener engineering commutator surge conductors rating universal potentiometer density permanent mechanical transducer capacity memory adc excitation two fuse pure harmonics application semiconductor inductor internal pmmc reaction welding resonance traction permeability breakers rms designed electromagnetic si generation brushes switching capacitive shaded rate 1 distribution resistor methods delta star oscillator reluctance simplification algebra 8085 boolean weston dynamometer insulating strength installation definition fuel heating earth units

8,450 questions

7,047 answers

132 comments

3,085 users

...