The field current of an under excited synchronous motor is increased while its load is constant. How will its power angle and power factor will change?
Question 2
Effective armature resistance Ra(eff.)of a synchronous machine is
Question 3
Which one of the following is the correct statement?
Question 4
What is the effect of the field failure of salient pole synchronous motor connected with infinite bus?
Question 5
The nature of armature mmf for a zero power factor lagging load in a 3-phase alternator is
Question 6
When two generators are operating together, an increase in governor set points on one of them:
1) Decrease the supply frequency
2) Increase in Power supply by that generator, while reducing the power supplied by the other one.
Which of the above statements is/are correct?
Question 7
Inverted V-curve is drawn between
Question 8
Consider the following statements: 1) Salient pole alternators have small diameters and large axial lengths. 2) Cylindrical rotor alternators have a distributed winding. 3) Cylindrical rotor alternators are wound for large number of poles. 4) Salinet pole alternators run at speeds slower than cylindrical rotor machines. Which of the above statements rotor machines.
Question 9
Match List-I (Test) with List-II (Object) and select the correct answer using the codes given below the lists:
List-I:
A. Slip test
B. Open circuited and zero power factor test
C. Sumpner’s test
D. Swinburne’s test
List-II:
1. Determination of full load copper losses of a transformer.
2. Determination of efficiency and constant losses of DC machine.
3. Determination of synchronous Potier reactance of synchronous machine.
4. Determination of direct and quadrature axis synchronous reactance of salient pole synchronous machine.
The correct order of sequence of List-I (A B C D) is
Question 10
Find the AC generator frequency, if generator has 20 poles at 1200 rpm speed?
