Electrical Machines Mock Test 5

10%

Question 1 of 10

1. Which is the correct relation below?

Pim = -Pog

Pim = -(Pog)*

Pim = (Pog)*

Pim = Pog

Question 1 of 10

Question 2 of 10

2. A salient pole synchronous generator has following per-unit parameter Xd = 1.2 pu, Xq = 0.8pu, ra = 0.25 ohms. Then the armature current at 0.8 lagging is?

1, 27°

1, 73°

1,-36.9°

1, 36.9°

Question 2 of 10

Question 3 of 10

3. A 315V, 3-phase 400 MVA alternator is running at leading power factor load at constant excitations. The most appropriate representation in space domain is?

Question 3 of 10

Question 4 of 10

4. The preferred order of calculating the voltage regulation is ___________

ZPF > ASA > MMF > EMF

EMF > ASA > ZPF > MMF

ZPF > MMF > ASA > EMF

ASA > MMF > ASA > EMF

Question 4 of 10

Question 5 of 10

5. Alternator on infinite bus bar has constant ___________

terminal voltage and frequency

frequency

power factor and terminal voltage

power factor

Question 5 of 10

Question 6 of 10

6. While finding the parameters for an alternator, its voltage regulation is found to be negative. Then the load connected to it must be __________

capacitive nature

inductive nature

resistive nature

can not be judged based on voltage regulation

Question 6 of 10

Question 7 of 10

7. For an underexcited 3 phase synchronous motor, connected to IBB is __________

absorbing reactive power from IBB

delivering zero reactive power to IBB

delivering reactive power to IBB

absorbing zero reactive power from IBB

Question 7 of 10

Question 8 of 10

8. Active power in synchronous machine is proportional to __________

torque

all of the mentioned

sinϕ

excitation

Question 8 of 10

Question 9 of 10

9. The V-curves of synchronous motor is plotted between ________

power factor vs If

If Vs Ia with constant shaft load

Ia Vs If with constant shaft load

power factor vs Ia

Question 9 of 10

Question 10 of 10

10. For a three phase synchronous motor, if the following condition is satisfied, it can be said that it is operating at ____________

Vt < Ef-Ia*ra

Lagging

Leading

Upf

Zpf

Question 10 of 10