Element of Electrical Design (3160918) MCQs

MCQs of GENERAL DESIGN ASPECTS

Showing 41 to 50 out of 84 Questions
41.

_________________ is equal to the energy consumed in magnetizing and demegnetizing a magnetic material.

(a)

Cu loss

(b)

Eddy current loss 

(c)

Hysteresis loss

(d)

All of these 

Answer:

Option (c)

42.

Wkg OR  Wm3   is the unit of 

(a)

Ph = hysteresis loss,

(b)

Bm =maximum flux density

(c)

Kh = hysteresis co-efficient

(d)

K = Steinmetz co-efficient

Answer:

Option (a)

43.

The eddy current loss depends on  

(a)

Maximum value of flux density 

(b)

Thickness and volume of material 

(c)

frequency magnetic flux revercel 

(d)

All of these

Answer:

Option (d)

44.

Which of the following is the equation of eddy emf (rms)?

(a)

22 π f x l Bm

(b)

2 ρ lb dx

(c)

2 π f Bm x b dxρ

(d)

π2 f2 Bm2  b l t36 ρ

Answer:

Option (a)

45.

Which of the following is the equation of eddy resistance of each path?

(a)

22 π f x l Bm

(b)

2 ρ lb dx

(c)

2 π f Bm x b dxρ

(d)

π2 f2 Bm2  b l t36 ρ

Answer:

Option (b)

46.

Which of the following is the equation of eddy current?

(a)

22 π f x l Bm

(b)

2 ρ lb dx

(c)

2 π f Bm x b dxρ

(d)

π2 f2 Bm2  b l t36 ρ

Answer:

Option (c)

47.

Which of the following is the equation of eddy current loss?

(a)

22 π f x l Bm

(b)

2 ρ lb dx

(c)

2 π f Bm x b dxρ

(d)

π2 f2 Bm2  b l t36 ρ

Answer:

Option (d)

48.

Generally, Total MMF or Ampere turns required in electrical rotating machines is given by 

(a)

MMF require for the iron part

(b)

MMF require for the Air gap

(c)

MMF require for the iron part + MMF require for the Air gap

(d)

MMF require for the iron part - MMF require for the Air gap

Answer:

Option (c)

49.

Which of the following must be minimized to reduce the total MMF required in the machine?

(a)

total length of an iron core 

(b)

length of frame 

(c)

length of airgap

(d)

all of these 

Answer:

Option (c)

50.

Which of the following factors is/are considered while calculating the MMF required for the airgap?

(a)

The average value of flux density must be taken into account to calculate the MMF required for the airgap.

(b)

The reluctance of the airgap with slotted armature will be more as compared to the smooth armature (core) machine.

(c)

The airgap reluctance for a machine having ventilation ducts will be more than a machine having no ventilation ducts.

(d)

All of these

Answer:

Option (d)

Showing 41 to 50 out of 84 Questions