Design of AC Machines (2170909) MCQs

MCQs of Design of Single-Phase Induction Motors

Showing 31 to 40 out of 56 Questions
31.

What is the formula of the output coefficient of single-phase induction motor?

(a)

C0 = 1.11 π2 Kw Bav ac 10-3

(b)

C0 = 11 Kw Bav ac 10-3

(c)

C0 = 11 * winding space factor * specific magnetic loading * specific electric loading * 10-3

(d)

All of these 

Answer:

Option (d)

32.

What is the formula of the kVA input if the rating of the machine is given in horsepower?

(a)

kVA input = horse power / ( 0.746 * efficiency * power factor )

(b)

kVA input = horse power * 0.746 * efficiency * power factor

(c)

kVA input = ( horse power * 0.746 ) / (efficiency * power factor)

(d)

kVA input = ( horse power * 0.746 * efficiency ) / power factor

Answer:

Option (c)

33.

In single-phase induction motor. What is the efficiency for the output watt of 750?

(a)

0.38

(b)

0.48

(c)

0.65

(d)

0.69

Answer:

Option (d)

34.

In single-phase induction motor. What is the power factor for the output watt of 750?

 

(a)

0.46

(b)

0.51

(c)

0.62

(d)

0.65

Answer:

Option (d)

35.

Output equation of single-phase induction motor = ___________ * Output equation of three-phase induction motos

 

(a)

3

(b)

1/3

(c)

2/3

(d)

3/2

Answer:

Option (c)

36.

In the design of single-phase induction motor. which of the following parameters affected by the value of Specific Magnetic loading (𝑩𝒂𝒗)?

(a)

Power Factor & Iron Losses 

(b)

Overload Capacity 

(c)

Size & Cost of the machine

(d)

All of these

Answer:

Option (d)

37.

In the design of single-phase induction motor. How many coils are present in the stator windings?

(a)

1

(b)

2

(c)

3

(d)

3 or more

Answer:

Option (d)

38.

In the design of single-phase induction motor. To the reduction of the MMF wave harmonics, __________ of the total slots are used for the main winding & _________ are used for accommodating the starting windings.

(a)

70%     30%     

(b)

30%     70%     

(c)

50%     50%     

(d)

75%     25%     

Answer:

Option (a)

39.

How can the small single phase motor reduce the harmonics still much further?

(a)

removing the winding

(b)

insulating the winding

(c)

grading the winding

(d)

shading the winding

Answer:

Option (c)

40.

In the design of single-phase induction motor. What is the formula for the mean pitch factor?

(a)

mean pitch factor = pitch factor of each coil per pole group + turns in the coil / total number of turns

(b)

mean pitch factor = pitch factor of each coil per pole group / turns in the coil * total number of turns

(c)

mean pitch factor = pitch factor of each coil per pole group * turns in the coil * total number of turns

(d)

mean pitch factor = pitch factor of each coil per pole group * turns in the coil / total number of turns

Answer:

Option (d)

Showing 31 to 40 out of 56 Questions