9 views
in Instrumentation and control by
 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

1 Answer

0 votes
by

 To turn a conducting SCR to off state, it is necessary to make : - anode current less than holding current

Related questions

0 answers 13 views

The conducting SCR turns-off when the on-state current is (A) below the latching current (B) below the holding current (C) equal to the reverse leakage current (D) zero 

asked Jun 4, 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 17 views

Transformer coupling is used in class A amplifier to make it : -  a) more efficient b) less bulky c) less costly d) distortion free

asked Apr 10, 2018 in Instrumentation and control 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 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
0 answers 19 views

Give some typical value of generated voltage in a power station. Why is it necessary to step up the voltage further before transmitting?

asked Apr 3, 2018 in Lesson 2 Generation, Transmission and Distribution of Electric Power an Overview by Shimroz123
1 answer 24 views

To determine the polarity of the voltage drop across a resistor, it is necessary to know?

asked Mar 25, 2018 in Network Analysis 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
0 answers 14 views

Once SCR starts conducting a forward current, its gate losses control over (A) Anode circuit voltage only (B) Anode circuit current only (C) Anode circuit voltage and current (D) None of the above

asked Apr 14, 2018 in Electrical 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 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
1 answer 17 views

State any four periodical maintenance which is necessary in transformer to achieve energy conservation.

asked Sep 22, 2018 in Energy Conservation And Audit by Shimroz123
7 answers 1,161 views

Draw the structural diagram of GTO. Explain briefly the switching behavior of GTO with the help of appropriate voltage and current waveform.

asked Aug 8, 2017 in Unit 1 by Zeeshan
1 answer 16 views

An inductor is connected in series with SCR to protect it from A) Excessive high voltage B) Excessive high dv/dt C) Excessive high di/dt D) Excessive large forward current 

asked Jun 18, 2018 in Inductor by Shimroz123
1 answer 21 views

SCR is more utilized as compared to Triac because it is

asked Apr 29, 2018 in Power Electronics by Shimroz123
2 answers 72 views

State what is the significance of conducting phasing out test on a 3-phase transformer? Explain its procedure with a suitable connection diagram.

asked Sep 15, 2018 by Shimroz123
1 answer 12 views

A thyristor (SCR) turns off when the  A) Gate pulse is removed B) Gate pulse is applied C) Thyristor current is below holding value D) Anode voltage is made negative

asked May 20, 2018 in Power Electronics by Shimroz123
1 answer 6 views

An SCR starts conducting with appreciable current when

asked May 15, 2018 in Power Electronics by Shimroz123
1 answer 9 views

Knowledge of Transfer Function is necessary for the calculation of: - a) The Time Constant b) The output for a given input c) The steady state gain d) The order of the system

asked Apr 14, 2018 in Instrumentation and control by Shimroz123
1 answer 35 views
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 8 views

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 

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
2 answers 19 views

A bipolar junction transistor (BJT) is used as a power control switch by biasing it in the cut-off region (OFF state) or in the saturation region (ON state). In the ON state, for the BJT  (A) both the base-emitter and base-collector junctions are reverse biased (B) the base-emitter junction is reverse ... (C) the base-emitter junction is forward biased, and the base-collector junction is reverse biased (D) both the base-emitter and base-collector junctions are forward biased

asked May 18, 2018 in Bipolar Junction Transistor by Shimroz123
1 answer 19 views

Filters with the ___ characteristic are useful when a rapid roll-off is required because it provides a roll-off rate greater than –20/dB/decade/pole:  (1) Butterworth (2) Chebyshev (3) Bessel (4) Elliptical 

asked Apr 9, 2018 in Electronics Engineering by Shimroz123
0 answers 94 views

The SCR would be turned OFF by voltage reversal of applied anode-cathode ac supply frequency of A) 10 kHz B) 10 Hz C) 5 kHz D) 5 Hz 

asked Jun 18, 2018 in Power Electronics by Shimroz123
1 answer 12 views

An SCR can only be turned off via it's   (A) cathode (B) anode (C) gates (D) none

asked May 16, 2018 in Power Electronics by Shimroz123
0 answers 11 views

Explain why potential difference is necessary to produce current in a circuit.

asked Jun 29 by Shimroz123
0 answers 19 views

The average time necessary for the correct sector of a disk to arrive at the read write head is  (1) Down time (2) Seek time (3) Rotational delay (4) Access time  

asked Apr 10, 2018 in Computer Engineering by Shimroz123
0 answers 17 views

One of the necessary and sufficient condition for a network function N(s)=p(s)/q(s) to be a transfer function is that  A) The coefficients of the polynomial p(s) and q(s) must be real and those for q(s) must be positive B) Coefficients of p(s) and q(s) must be real and positive C) Coefficients of p(s) must be positive and real but coefficients of q(s) can be negative also D) Degree of p(s) and q(s) may differ by either zero or one only

asked Apr 9, 2018 in Electronics Engineering by Shimroz123
0 answers 17 views

For measuring the frequency of an unknown A.C. source. Which of the following device is necessary to obtain a standard waveform?  (A) Operational amplifier (B) Astable multivibrator (C) Schmitt trigger (D) Monostable multivibrator

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
0 answers 20 views

A toothed type Tacho-generator has 60 teeth. A magnetic pickup is used in conjunction with it. The number of pulses generated per second in the magnetic pick up is : -  a) 3000 b) 1500 c) 1800 d) 1200

asked Apr 10, 2018 in Instrumentation and control by Shimroz123
1 answer 16 views

A 100 turn coil has an inductance of 6 mH. If the number of turns is increased to 200, all other quantities remaining the same, the inductance will be:

asked May 22, 2018 in Inductance by Shimroz123
1 answer 70 views

what is the minimum voltage required to turn on a diode ?

asked Dec 28, 2017 in Electrical Engineering by Quiz
0 answers 26 views

An audit trail  (1) is used to make backup copies (2) is the recorded history of operations performed on a file (3) can be used to restore lost information (4) none of these

asked Apr 10, 2018 in Computer Engineering by Shimroz123
0 answers 20 views

A synchronous machine connected to a power system grid bus-bar is operating as a generator. To make the machine operate as a motor, the  (1) direction of rotation is to be reversed (2) phase sequence is to be changed (3) field excitation is to be decreased (4) mechanical input is to be less than the losses at the shaft

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

State any four properties of conducting materials.

asked Sep 4, 2018 by Shimroz123
1 answer 20 views

The necessary and sufficient condition for a rational function of, T(s) to be driving point impedance of an RC network is that all poles and zeros should be

asked Apr 29, 2018 in Network Analysis 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 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
1 answer 12 views

Pinch off voltage of a J FET is the drain to source voltage above which drain current. • Increases • Decreases • Remains constant • Becomes zero

asked May 14, 2018 in Electronics Engineering by Shimroz123
1 answer 31 views

In a 741 Op-Amp, there is 20 dB/decade fall-off starting at a relatively low frequency. This is due to the (A) applied load (B) internal compensation (C) impedance of the source (D) power dissipation in the chip

asked Apr 26, 2018 in Electronics Engineering by Shimroz123
1 answer 32 views

Impurity atoms to be added to pure silicon in order to make a p-type semiconductor belongs to (a) Phosphorous (b) Boron (c) Antimony (d) Aluminium 

asked May 25, 2018 in Semiconductor by Shimroz123
0 answers 15 views

The state of a process after it encounters an I/O instruction is __________.  (1) Ready (2) Blocked/Waiting (3) Idle (4) Running 

asked Apr 10, 2018 in Computer 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

3,084 users

...