Electrical Machines Mock Test 4

10%

Question 1 of 10

1. The manufacturer has mentioned a medium starting torque and 15% speed regulation. Which is the most appropriate motor for this requirement?

dc shunt motor

differential motor

induction motor

none of the mentioned

Question 1 of 10

Question 2 of 10

2. Retardation test on DC shunt motor is used for finding _______

copper losses

iron losses

stray losses

friction losses

Question 2 of 10

Question 3 of 10

3. Load angle δ is the angle between ____________

rotor MMF F_r and resultant MMF F_R

stator MMF F_s and rotor MMF F_r

stator MMF F_s and resultant MMF F_R (or) rotor MMF F_r and resultant MMF F_R

stator MMF F_s and resultant MMF F_R

Question 3 of 10

Question 4 of 10

4. Interpoles are used to start the dc motor above the base speed.

False

True

Question 4 of 10

Question 5 of 10

5. Centrifugal pumps, fans-blowers use __________

only shunt motors

none of the mentioned

shunt as well as induction motor

only induction motor

Question 5 of 10

Question 6 of 10

6. There is an application which required pulsating loads, punch presses. The most preferred machines would be __________

series dc machine

shunt dc machine

compound dc machine

all of the mentioned

Question 6 of 10

Question 7 of 10

7. If the field current and armature current are reversed, then the __________

direction of rotation reverses

stops

direction of rotation remains same

none of the mentioned

Question 7 of 10

Question 8 of 10

8. The excitation system and speed of alternator has _______

exponential response

rectangular hyperbola response

circular response

linear response

Question 8 of 10

Question 9 of 10

9. Interpoles provide mmf more than armature mmf in a dc machine.

False

True

Question 9 of 10

Question 10 of 10

10. The qualities aspired to obtain a good permanent magnet is/are ____________

high residual flux and high coercivity

high coercivity

low coercivity

high residual flux

Question 10 of 10