Design of Electrical Machines Mock Test 9

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Question 1 of 10

1. What is the relation between pole pitch and the magnetizing reactance?

magnetizing reactance is indirectly proportional to the square of the pole pitch

magnetizing reactance is indirectly proportional to the pole pitch

magnetizing reactance is directly proportional to the square of the pole pitch

magnetizing reactance is directly proportional to the pole pitch

Question 1 of 10

Question 2 of 10

2. What is the formula for the pole pitch in the universal commutator motor?

pole pitch = 3.14 * diameter * 2 * no. of poles

pole pitch = 3.14 * diameter * 2 / no. of poles

pole pitch = 3.14 / diameter * 2 * no. of poles

pole pitch = 3.14 * diameter / 2 * no. of poles

Question 2 of 10

Question 3 of 10

3. What is the concept of notching operation?

process of decreasing the voltage

process of cutting out the resistance

process of increasing the efficiency

process of adding on the resistance

Question 3 of 10

Question 4 of 10

4. What is the thickness of the laminations of magnetic poles?

0.4-0.5 mm

0.2-0.4 mm

0.35-0.5 mm

0.3-0.5 mm

Question 4 of 10

Question 5 of 10

5. What is the value of the specific electric loading for the continuous duty motor type?

12000-20000 A per m

15000-25000 A per m

6000-9000 A per m

8000-11000 A per m

Question 5 of 10

Question 6 of 10

6. What is the formula of the ratio of the lower limit to upper limit of current with respect to the resistance?

lower limit of current / upper limit of current = (motor resistance / resistance to limit the starting current)^{1/number of resistance}

lower limit of current / upper limit of current = (motor resistance * resistance to limit the starting current)^{1/number of resistance}

lower limit of current / upper limit of current = motor resistance / resistance to limit the starting current

lower limit of current / upper limit of current = motor resistance * resistance to limit the starting current

Question 6 of 10

Question 7 of 10

7. The high values actually apply for the small motors below 150 W.

true

false

Question 7 of 10

Question 8 of 10

8. For what outputs are the 2 pole machines made use of?

output > 200 W

output < 300 W

output > 300 W

output < 200 W

Question 8 of 10

Question 9 of 10

9. What is the symbol used for the terminal voltage in dc motor design?

Question 9 of 10

Question 10 of 10

10. What is the formula for the saturation factor?

saturation factor = total mmf required for the magnetic circuit * mmf required for air gap

saturation factor = total mmf required for the magnetic circuit - mmf required for air gap

saturation factor = total mmf required for the magnetic circuit/mmf required for air gap

saturation factor = total mmf required for the magnetic circuit + mmf required for air gap

Question 10 of 10