243 views
in Electrical Engineering by
A three phase breaker is rated at 2000 MVA, 33 kV, its making current is 

(A) 70 kA (B) 89 kA (C) 49 kA (D) 35 kA 

Your answer

Thanks for your contribution. Feel free to answer this question. Please avoid short answer. Your answer is most welcome. Be genuine.

Upload image or document:

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
Are you a robot ? (Y = Yes / N = No)
To avoid this verification in future, please log in or register.

Related questions

0 answers 78 views

A 3-phase circuit breaker is rated at 1250 A, 2000 MVA, 33 kV, 4s. Its making current capacity will be   (a) 35 kA (b) 89 kA (c) 79 kA (d) 69 kA

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
1 answer 59 views

A three-phase, 33 kV oil circuit breaker is rated 1200 A, 2000 MVA, 3 s. The symmetrical breaking current is  (A) 1200 A (B) 3600 A (C) 35 kA (D) 104.8 kA

asked May 25, 2018 in Power system by Shimroz123
1 answer 42 views

A 50 Hz, 4-pole, 500 MVA, 22 kV turbo-generator is delivering rated megavolt amperes at 0.8 power factor. Suddenly a fault occurs reducing in electric power output by 40%. Neglect losses and assume constant power input to the shaft. The accelerating torque in the generator in MNm at the time of fault will be  (A) 1.528 (B) 1.018 (C) 0.848 (D) 0.509

asked May 25, 2018 in Power system by Shimroz123
1 answer 148 views

A 50 Hz, 4 pole turboalternator rated at 20 MVA. 13.2 KV has an inertia constant H = 4 KW sec/KVA. The K.E. stored in the rotor at synchronous speed is

asked May 3, 2018 in Electric Power Transmission by Shimroz123
0 answers 109 views

A single phase transformer rated at 3000 kVA, 69 kV 4.16 kV, 60 Hz has a total internal impedance Zp of 127 ohm, referred to the primary side. Calculate the primary current if the secondary is accidentally short circuited.  (A) 43.5 A (B) 543 A (C) 9006 A (D) 721 A 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 118 views

A 60 Hz, 4 pole turbo generator rated 100 MVA, 13.8 KV has an inertia constant of 10 MJ/MVA. Find the stored energy in the rotor at synchronous speed.  (A) 10 MJ (B) 100 J (C) 1000 J (D) 1000 MJ 

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

A Phase shift transformer is designed to control 150 MVA on a 230 kV, 3 phase line. The phase angle is variable between zero and 15 deg. Calculate the approximate basic power rating of the transformer.  (A) 150 MVA (B) 56 MVA (C) 75 MVA (D) 750 MVA 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 26 views

A 500 MW, 3-phase, Y-connected synchronous generator has a rated voltage of 21.5 kV at 0.85 p.f. The line current when operating at full load rated conditions will be  (A) 13.43 kA (B) 15.79 kA (C) 23.25 kA (D) 27.36 kA

asked May 17, 2018 in Synchronous machine by Shimroz123
0 answers 189 views

A 30 MVA, 13.2 KV synchronous generator has a solidly grounded neutral. Its positive, negative and zero sequence impedances are 0.30, 0.40 and 0.05 pu respectively. What value of reactance must be placed in the generator neutral so that the fault current for a line to ground fault of zero fault impedance shall not exceed the rated line current.  (A) 4.416 ohm (B) 8.8 ohm (C) 2.08 ohm (D) 10.2 ohm 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 15 views

A three-phase cage induction motor is started by direct-on-line (DOL) switching at the rated voltage. If the starting current drawn is 6 times the full load current, and the full load slip is 4%, then ratio of the starting developed torque to the full load torque is approximately equal to (A) 0.24 (B) 1.44 (C) 2.40 (D) 6.00

asked May 17, 2018 in Induction Machine by Shimroz123
1 answer 15 views

A 3-phase star-connected 75 MVA, 25 kV 3-phase synchronous generator has a synchronous reactance of 1.0 p.u. The per unit value to a 90 MVA base and 30 kV is (A) 2/15 p.u. (B) 5/6 p.u. (C) 1.0 p.u. (D) 1.2 p.u.

asked Apr 25, 2018 in Electrical Engineering by Shimroz123
0 answers 555 views

A 30 MVA, 15 KV, 1500 rpm, 3 phase synchronous generator connected to a power grid has a synchronous reactance of 9 ohm per phase. If the exciting voltage is 12 kV (line to neutral) and the system voltage is 17.3 kV (line to line), Calculate the maximum power that generator can deliver before it falls out of step (losses synchronous).  (A) 39.952 MW (B) 78.349 MW (C) 16.67 MW (D) 112.89 MW

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 65 views

The inertia constant of a 100 MVA, 11 kV water wheel generator is 4. The energy stored in the rotor at the synchronous speed is: A) 400 Mega Joule B) 400 Kilo Joule C) 25 Mega Joule D) 25 Kilo Joule

asked Jun 4, 2018 in Power system by Shimroz123
1 answer 19 views

A 20-MVA, 6.6-kV, 3-phase alternator is connected to a 3-phase transmission line. The per unit positive-sequence, negative-sequence and zero-sequence impedances of the alternator are j0.1, j0.1 and j0.04 respectively. The neutral of the alternator is connected to ground through an inductive reactor of j0.05 p.u. The per unit positive-, ... The voltage of the alternator neutral with respect to ground during the fault is  (A) 513.8 V (B) 889.9 V (C) 1112.0 V (D) 642.2 V

asked May 25, 2018 in Power system by Shimroz123
1 answer 11 views

Making current of a circuit breaker refers to: (1) Steady state rated current (2) Average value of transient short circuit current (3) R.M.S. value of the short circuit current at the the time of major peak (4) Equal to the fault current

asked May 22, 2018 in Circuit breaker by Shimroz123
0 answers 17 views

A three phase 50 Hz, 400 kV transmission line is 300 km long. The line inductance is 0.97 mH/km per phase and capacitance is 0.0115 mF/km per phase. Assume a loss less line. Determine the line wavelength (a line phase constant).  (A) 1250 km (B) 6578 km (C) 4990 km (D) 2445 km 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
0 answers 8 views

A separately excited dc generator is running at rated speed and at no load. If its field winding is suddenly connected to a dc source then rise in armature generated voltage is governed by (1) Armature time constant (2) Field time constant (3) Both (a) and (b) (4) Mechanical time constant

asked Apr 11, 2018 in Electrical Engineering by Shimroz123
0 answers 21 views

A synchronous motor is delivering 80% of its rated output and is operating at UPF. If its excitation is increased, then  (1) the output delivered gets increased (2) its pf becomes lagging (3) the output delivered gets decreased (4) its pf becomes leading

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
1 answer 80 views

The locked rotor current in a 3-phase, star connected 15 , kW 4 , pole 230 V , 50 Hz induction motor at rated conditions is 50 A. Neglecting losses and magnetizing current, the approximate locked rotor line current drawn when the motor is connected to a 236 , V 57 Hz supply is  (A) 58.5 A (B) 45.0 A (C) 42.7 A (D) 55.6 A

asked May 17, 2018 in Electrical Machine by Shimroz123
0 answers 308 views

Two generating stations G1 and G2 of ratings 10 MVA and 8 MVA respectively are linked by a line rated at 5 MVA, 0.1 Pu reactance. Each station has a reactance of 0.5 pu. If the base MVA is 10 MVA, short-circuit MVA of G1 is

asked May 24, 2018 in Power system by Shimroz123
1 answer 46 views

A 100 MVA, 11 KV, 3-phase, 50 Hz, 8—pole synchronous generator has an inertia constant H equal to 4 seconds. The stored energy in the rotor of the generator at synchronous speed will be  A) 100 MJ B) 400 MJ C) 800 MJ D) 12.5 MJ

asked May 20, 2018 in Synchronous machine by Shimroz123
1 answer 33 views

A 400 V, 50 Hz 30 hp, three-phase induction motor is drawing 50 A current at 0.8 power factor lagging. The stator and rotor copper losses are 1.5 kW and 900 W respectively. The friction and windage losses are 1050 W and the core losses are 1200 W. The air-gap power of the motor will be (A) 23.06 kW (B) 24.11 kW (C) 25.01 kW (D) 26.21 kW

asked May 17, 2018 in Electrical Machine by Shimroz123
1 answer 63 views

The corona loss of a 3-phase transmission line is 100 kW at 60 kV/phase and 25 kW at 50 kV/phase. The disruptive critical voltage is (A) 40 kV (B) 43.6 kV (C) 49.6 kV (D) 50 kV

asked Apr 25, 2018 in Electrical Engineering by Shimroz123
1 answer 12 views

In a certain three -wire Y -connected generator, the phase voltages are 2 kV. The magnitudes of the line voltages will be: A. 2,000 V B. 6,000 V C. 666 V D. 3,464 V

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

Three single phase transformers are connected in delta-delta to step down a line voltage of 138 kV to 4160 V to supply power to a production plant. The plant draws 21 MW at a lagging power factor of 86 %. Calculate the apparent power furnished by the HV line.  (A) 24.4 MVA (B) 48.8 MVA (C) 12.2 MVA (D) 6.1 MVA 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 19 views

A 1000W heater is rated to operate at a direct current (DC) of 10A. If the heater is supplied alternating current (AC) for producing the same quantity of heat the value of current should be  a. Iav=10A b. Irms=10A c. Ipeak=10A 

asked May 17, 2018 in Electrical Engineering 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 23 views

The per unit impedance of a circuit element is 0.30. If the base kV and base MVA are halved, then the new value of the per unit impedance of the circuit element will be:  (A) 0.3 (B) 0.6 (C) 0.003 (D) 0.006 

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 51 views

If voltage at the two ends of a transmission line is 132 kV and its reactance is 40 Ohms, the capacity of the line will be: (A) 435.6 MW (B) 217.8 MW(C) 251.5 MW (D) 500 MW

asked Apr 11, 2018 in Computer Engineering by Shimroz123
1 answer 17 views

A three-phase star -connected load is operating at a power factor angle ϕ  with ϕ being the angle between

asked Apr 25, 2018 in Electrical Engineering by Shimroz123
1 answer 19 views

At slip equal to infinity, the torque of a three phase induction motor is :-  a) zero b) very small c) high d) very high

asked Apr 11, 2018 in Electrical Engineering by Shimroz123
1 answer 16 views

An alternator is delivering rated current at rated voltage and 0.8 power-factor lagging. For delivering rated current at rated voltage and 0.8 poWer—factor leading, the required excitation will be:  (A) less  (B) more (C) more or less (D) the same

asked Apr 9, 2018 in Electrical Engineering by Shimroz123
1 answer 13 views

In a three-phase system, when the loads are perfectly balanced, the value of neutral current is equal to: A. Zero B. One-third of the maximum value C. Two -third of the maximum value D. The maximum value

asked Apr 12, 2018 in Electrical Engineering by Shimroz123
2 answers 95 views

The sending end and receiving end voltages of a three-phase transmission line are 10 kV/ph and 9.5 kV/ph, respectively. If the resistance drop is 150 V/ph and receiving end power factor is 0.8, the sending end power factor is (A) 0.745 lagging (B) 0.775 lagging (C) 0.8 lagging (D) 0.85 lagging

asked Apr 28, 2018 in Power system by Shimroz123
1 answer 17 views

A 3-phase induction motor is driving a constant torque load at rated voltage and frequency. If both voltage and frequency are halved, following statements relate to the new condition if stator resistance, leakage reactance and core loss are ignored  1. The difference between synchronous speed and actual speed remains same 2. The airgap flux remains same 3. The ... . slip remains same Among the above, current statements are  (A) All (B) 1, 2 and 3 (C) 2, 3 and 4 (D) 1 and 4

asked May 18, 2018 in Induction Machine by Shimroz123
1 answer 22 views

The r.m.s. value of a sinusoidal A.C. current is equal to its value at an angle of______degrees.

asked Mar 24, 2018 in Electrical Engineering by Shimroz123
1 answer 18 views

A 50 kW dc shunt is loaded to draw rated armature current at any given speed. When driven  (i) at half the rated speed by armature voltage control and (ii) at 1.5 times the rated speed by field control, the respective output powers delivered by the motor are approximately. (A) 25 kW in (i) and 75 kW in (ii) (B) 25 kW in (i) and 50 kW in (ii) (C) 50 kW in (i) and 75 kW in (ii) (D) 50 kW in (i) and 50 kW in (ii)

asked May 17, 2018 in DC machine by Shimroz123
1 answer 18 views

A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is  (A) magnetizing (B) demagnetizing (C) cross-magnetizing (D) ineffective

asked May 17, 2018 in Synchronous machine by Shimroz123
1 answer 62 views

If the inertia constant H of a machine of 200 MVA is 2 p.u., its value corresponding to 400 MVA will be   (a) 4 p.u. (b) 2 p.u. (c) 1.0 p.u. (d) 0.5 p.u. 

asked May 13, 2018 in Electrical Engineering by Shimroz123
1 answer 26 views

A generator is connected through a 20 MVA, 13.8/138 kV step down transformer, to a transmission line. At the receiving end of the line a load is supplied through a step down transformer of 10 MVA, 138/69 kV rating. A 0.72 pu. load, evaluated on load side transformer ratings as base values , is supplied from the above system. For system base values of 10 MVA and 69 kV in load circuit, the value of the load (in per unit) in generator will be (A) 36 (B) 1.44 (C) 0.72 (D) 0.18

asked May 25, 2018 in Power system by Shimroz123
0 answers 22 views

A three phase transformer can be used in emergency at reduced rating of 58% to deliver three phase power when it is connected (a) in star-delta (b) delta-star (c) star-star (d) delta-delta

asked Apr 14, 2018 in Electrical Engineering by Shimroz123
0 answers 20 views

A three phase transmission line delivers a load of 5 MW at 0.8 power factor lagging. Resistance of each conductor is 0.5 ohm / km. Receiving end voltage is 33 kV. If the line loss is not to exceed 10%, determine the length of the line.  (A) 7 km (B) 27.9 km (C) 56.8 km (D) 13.9 km

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
0 answers 24 views

The sending and receiving end voltages of a three phase transmission line at 100 MW load are equal at 230 KV. The phase line impedance is j14 ohm. Calculate the maximum steady state power that can be transmitted over the line.  (A) 3778.5 MW (B) 2234.56 MW (C) 1784.19 MW (D) 512.37 MW

asked Apr 5, 2018 in Electrical Engineering by Shimroz123
1 answer 55 views

How many insulator disc used for 33 kV transmission voltage line?

asked Dec 5, 2017 in Electric Power Transmission by Quiz
1 answer 15 views

An unsaturated dc shunt motor runs at its rated speed when rated voltage is applied to it. If the supply voltage to the motor is reduced by 25%, the speed of the motor  (a) Increases by 25% (b) Remains the same (c) Decreases by 25% (d) Decrease only slightly by an amount less than 25% 

asked May 13, 2018 in Power Electronics by Shimroz123
0 answers 20 views

An alternator is connected to a bus. For a symmetrical fault at the bus, the fault level is 60 MVA. If another alternator is connected to the same bus, the new fault level will be (1) 120 MVA (2) 60 MVA (3) 30 MVA (4) 15 MVA 

asked Apr 11, 2018 in Electrical Engineering by Shimroz123
1 answer 19 views

If the fault current is 2000 A, the relay setting is 50% and CT ratio is 400:5, the plug setting multiplier will be

asked Apr 29, 2018 in Power system by Shimroz123
0 answers 18 views

The method of speed control used for increasing the speed of a dc shunt motor above its rated speed is  1) armature resistance control 2) field control (3) armature voltage control (4) series parallel control 

asked Apr 10, 2018 in Electrical Engineering by Shimroz123
1 answer 115 views

A 500 MVA, 11 KV synchronous generator has 0.2 p.u. synchronous reactance. The p.u. synchronous reactance on the base values of 100 MVA and 22 KV is  A) 0.16 B) 0.01 C) 4.0 D) 0.25

asked May 17, 2018 in Synchronous machine 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

8,516 questions

7,114 answers

135 comments

3,090 users

...