# Draw sinusoidal waveform of 3 phase emf and indicate the phase sequence.

12 views
Draw sinusoidal waveform of 3 phase emf and indicate the phase sequence.

## 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): Email me at this address if my answer is selected or commented on: Privacy: Your email address will only be used for sending these notifications.

## 1 Answer

0 votes

Phase sequence is R-Y-B.

## Related questions

1 answer 10 views

What is Phase sequence? Draw waveforms of 3 phase emf.

1 answer 58 views

Draw the waveform of three phase AC supply voltage.

1 answer 10 views

The direction of rotation of a 3-phase induction motor is clockwise when it is supplied with 3-phase sinusoidal voltage having phase sequence A-B-C. For counter clockwise rotation of the motor, the phase sequence of the power supply should be  (A) B-C-A (B) C-A-B (C) A-C-B (D) B-C-A or C-A-B

1 answer 24 views

Draw the circuit diagram of bridge rectifier with π filter. Draw its input and output waveform.

1 answer 283 views

The sequence components of current of a single-phase load connected to a 3-phase system are (A) equal positive and negative sequence components (B) equal positive, negative and zero sequence components (C) vector sum of sequence currents is zero (D) algebraic sum of sequence currents is zero

0 answers 17 views

The phase sequence of a 3 phase alternator is RBY. If the direction of rotation of field is reversed, then which of the following can be the phase sequence ? (A) RBY (B) BYR (C) BRY (D) YRB

0 answers 22 views

If the supply frequency of a 3-phase induction motor is ‘f’, then frequency of rotor emf at motor slip ‘s’ will be   (a) sf (b) (1 – s)f (c) f/s (d) None of these

1 answer 32 views

Draw the power and control circuit diagram for forward — stop — Reverse type DOL starter for 3 phase induction motor.

1 answer 9 views

Draw and explain star delta starter for 3 phase induction motor

1 answer 11 views

In a dc-ac 3-phase MOSFET bridge inverter circuit, the switches are marked in a sequence as 1, 2, 3 in the top-half and 4, 5, 6 in the bottom half of the bridge. The triggering sequence of switches that gives balanced output voltage is (A) 1, 2, 3, 4, 5, 6 (B) 1, 5, 3, 4, 2, 6 (C) 1, 6, 2, 4, 3, 5 (D) 1, 4, 2, 5, 3, 6

2 answers 61 views

for Delta-Star connection of 3-phase transformer: i) Draw the connection diagram ii) List any two advantages of this connection iii) State its area of application.

1 answer 11 views

Draw the symbol and state the applications of : 1) Push button switch 2) Selector switch 3) Solenoid valve 4) Limit switch

0 answers 16 views

Total numbers of ascending runs in the sequence 4 6 7 2 9 1 2 8 9 3 0  (1) 3 (2) 5 (3) 7 (4) 9

1 answer 48 views

The output voltage waveform of a three-phase square-wave inverter contains  (A) only even harmonics (B) both odd and even harmonic (C) only odd harmonics (D) only triple harmonics

1 answer 71 views

A single-phase voltage source square -wave inverter feeds pure inductive load. The waveform of the load current will be

1 answer 7 views

Two wattmeters connected to measure the power input to a balanced three-phase circuit indicate 4.5 KW and 3 KW respectively. Find the power factor of the circuit. A. 0.7 B. 0.8 C. 0.95 D. 0

0 answers 24 views

The stator mmf and rotor mmf of a 3-phase induction motor (A) are equal (B) rotate with slip speed (C) are opposite but rotate with synchronous speed (D) rotate with the same rotor speed

1 answer 13 views

A 500 kVA, 3-phase transformer has iron losses of 300 W and full load copper losses of 600 W. The percentage load at which the transformer is expected to have maximum efficiency is  (A) 50.0% (B) 70.7% (C) 141.4% (D) 200.0%

1 answer 21 views

At a particular instant, the R-phase voltage of a balanced 3-phase system is + 30 V, and the Y-phase voltage is – 90 V. The voltage of B-phase at that instant is (A) + 120 V (B) – 120 V (C) – 60 V (D) + 60 V

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

1 answer 27 views

The rotor power output of a 3 -phase induction motor is 15 kW and the corresponding slip is 4%. The rotor copper losses will be: (A) 600 W (B) 625 W (C) 650 W (D) 700 W

1 answer 8 views

Draw neat labeled diagram of single phase AC locomotive showing its various equipments of power circuit and give function of each equipment used in power circuit.

1 answer 9 views

State the use of:- (i) Clip-on-ammeter (ii) Phase sequence indicator

1 answer 24 views

State the application of phase sequence indicator; clip on ammeter, frequency meter & P.F. meter.

1 answer 19 views

The phase sequence of a three-phase alternator will reverse if  A) The field current is reversed keeping the direction of rotation same. B) The field current remains the same but the direction of rotation is reversed C) The field current is reversed and also the direction of rotation is reversed D) None of the above

0 answers 29 views

Draw the Delta connected three phase system showing all the voltages and currents. Write the power equation.

1 answer 14 views

In a two -channel oscilloscope operating in x -y mode, two in -phase 50 Hz sinusoidal waveforms of equal amplitude are fed to the two channels. What will be the resultant pattern on the screen ? (a) An ellipse (b) A parabola (c) Straight line inclined at 45° with respect to x-axis (d) A circle

1 answer 26 views

When the phase difference between two sinusoidal quantities is 90° they are said to be ______ A) Phase right angle B) Phase quadrature C) Phase sinuright D) None of these

1 answer 25 views

Two sinusoidal signals having the same amplitude and frequency are applied to the X and Y inputs of a CRO. The observed Lissajous figure is straight line. The phase shift between the two signals would be (1) Zero (2) 90 degrees (3) Either zero or 180 degrees (4) Either 90 degrees or 270 degrees

1 answer 8 views

The rms value of the current in a wire which carries a d.c. current of 10 A and a sinusoidal alternating current of peak value 20 A is  (A) 10 A (B) 14.14 A (C) 15 A (D) 17.32 A

1 answer 6 views

Draw ladder diagram for following sequence: i) When NO START Pushbutton is pressed Green light is on. ii) When NC STOP Pushbutton is pressed Red light is on. Green light goes off.

1 answer 19 views

Explain full wave bridged rectifier with the help of circuit diagram and input output waveform.

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%

0 answers 19 views

Two 3-phase synchronous generators with reactance 60% and 40% feed a fault current of 1200 A up to short-circuit fault point. The short-circuit current is (A) 1200 A (B) 2400 A (C) 4000 A (D) 5000 A

1 answer 10 views

No-load test on a 3-phase induction motor was conducted at different supply voltage and a plot of input power versus voltage was drawn. This curve was extrapolated to intersect the y-axis. The intersection point yields  (A) Core loss (B) Stator copper loss (C) Stray load loss (D) Friction and windage loss

1 answer 15 views

Measurement of power and power factor of a 3-phase system by two wattmeter method can be obtained in case of  1. Balanced load and balanced source  2. Balanced source with 3-phase 3-wire unbalanced load  3. Unbalanced source with 3-phase 3-wire balanced load  4. Balanced source with 3-phase 4-wire unbalanced load  5. unbalanced and unbalanced source    (a) 1 only (b) 2, 3 and 5 (c) 1, 2, 3, 4 and 5 (d) 1, 2, 3 and 5

0 answers 14 views

A 3-phase, 50 Hz, 500 V induction motor develops 20 hp at slip of 5%. Mechanical losses are 1 hp, and stator loss is 1 kW. The efficiency will be   (a) 95.3% (b) 90.5% (c) 91.3% (d) 85.3%

1 answer 24 views

Describe the power and control circuit for automatic Star-Delta starter for 3-phase induction motor.

0 answers 52 views

A 220 kV, 3 phase transmission line is 60 km long. The resistance is 0.15 ohm / km and the inductance is 1.4 mH / km. Use the short line model to find the power at the sending end when the line is supplying a three phase load of 300 MVA at 0.8 pf lagging at 220 kV.  (A) 5.58MW (B) 80MW (C) 85.58MW (D) 74.42 MW

1 answer 4 views

Explain negative phase sequence protection of alternator.

1 answer 35 views

Define phase sequence of three phase supply with waveforms. What is normal phase sequence? Which 3 standard colours are used to denote the phase sequence?

1 answer 91 views

An alternator has a phase sequence of RYB for its phase voltage. In case the direction of rotation of alternator is reversed, the phase sequence will become?

1 answer 19 views

Draw and explain RC phase shift Oscillator.

0 answers 23 views

Draw and explain capacitor start capacitor run single phase induction motor.

0 answers 11 views

A single-phase half-controlled rectifier is driving a separately excited dc motor. The dc motor has a back emf constant of 0.5 V/rpm. The armature current is 5 A without any ripple. The armature resistance is 2 Ohm. The converter is working from a 230 V, single-phase ac source with a firing angle of 30o . Under this operating condition, the speed of the motor will be  (A) 339 rpm (B) 359 rpm (C) 366 rpm (D) 386 rpm

0 answers 26 views

When a line -to -ground fault occurs, the current in a faulted phase is 100A. The negative sequence current in this case will be : (A) Zero (B) 33.3 A (C) 66.6 A (D) 100 A

0 answers 21 views

If the back emf of a dc motor is doubled and its speed is also doubled, the torque developed in the machine will  (1) get doubled (2) become 4 times (3) get halved (4) remain unaltered

0 answers 46 views

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

1 answer 18 views

A 3-phase fully controlled bridge converter with free wheeling diode is fed from 400 V, 50 Hz AC source and is operating at a firing angle of 60o. The load current is assumed constant at 10 A due to high load inductance. The input displacement factor (IDF) and the input power factor (IPF) of the converter will be  (A) IDF IPF = = 0.867; 0.828 (B) IDF IPF = = 0.867; 0.552 (C) IDF IPF = = 0.5; 0.478 (D) IDF IPF = = 0.5; 0.318

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