MCQs of GENERAL DESIGN ASPECTS (Element of Electrical Design - 3160918)

Element of Electrical Design (3160918) MCQs

MCQs of GENERAL DESIGN ASPECTS

Showing 61 to 70 out of 84 Questions

61.

Calculate Gap contraction factor for the slot (K_gs) from the following data:

no. of pole = 4

slot pitch = 43 mm

slot opening = 21 mm

gross length of core = 480 mm

pole arc = 180 mm

length of airgap = 6 mm

flux per pole = 0.056 Wb

no. of ventilation ducts = 8

width of each ventilating duct = 12 mm

carter's coefficient for slot = 0.42

carter's coefficient for ducts = 0.28

(a)	1.258
(b)	1.059
(c)	0.648
(d)	4145

62.

Calculate Gap contraction factor for the duct (K_gd) from the following data:

no. of pole = 4

slot pitch = 43 mm

slot opening = 21 mm

gross length of core = 480 mm

pole arc = 180 mm

length of airgap = 6 mm

flux per pole = 0.056 Wb

no. of ventilation ducts = 8

width of each ventilating duct = 12 mm

carter's coefficient for slot = 0.42

carter's coefficient for ducts = 0.28

(a)	1.258
(b)	1.059
(c)	0.648
(d)	4145

63.

Calculate flux density at the pole center (B_g) in Wb/m², from the following data:

no. of pole = 4

slot pitch = 43 mm

slot opening = 21 mm

gross length of core = 480 mm

pole arc = 180 mm

length of airgap = 6 mm

flux per pole = 0.056 Wb

no. of ventilation ducts = 8

width of each ventilating duct = 12 mm

carter's coefficient for slot = 0.42

carter's coefficient for ducts = 0.28

(a)	1.258
(b)	1.059
(c)	0.648
(d)	4145

64.

Calculate MMF required for the Airgap (AT_g) in A, from the following data:

no. of pole = 4

slot pitch = 43 mm

slot opening = 21 mm

gross length of core = 480 mm

pole arc = 180 mm

length of airgap = 6 mm

flux per pole = 0.056 Wb

no. of ventilation ducts = 8

width of each ventilating duct = 12 mm

carter's coefficient for slot = 0.42

carter's coefficient for ducts = 0.28

(a)	1.258
(b)	1.059
(c)	0.648
(d)	4145

65.

Calculate Airgap length (l_g) in mm, from the following data:

Gap contraction factor for the slot = 1.1765

Gap contraction factor for the duct = 1.0300

Gap flux density at pole center = 0.65 Wb/m²

Field MMF per pole = 3800 A

MMF required for iron part of the magnetic circuit = 600 A

(a)	0.005
(b)	0.05
(c)	0.5
(d)	5

66.

Why calculation of MMF for Teeth is difficult?

(a)	MMF calculation are depend on teeth shape & type.
(b)	Tapered teeth have varying flux densities over the length of teeth.
(c)	Due to the high flux density in the teeth, the actual flux passing through the teeth is will be less than the airgap flux.
(d)	All of these

67.

Which of the following method is not used to find MMF required for the tapered teeth?

(a)	Graphical method
(b)	Carter's method
(c)	simpson's rule
(d)	Flux density at (1/3)^rd section

68.

Select the best option which defines the Graphical method for the calculation of MMF for teeth.

(a)	Find different H values for the different distances of teeth from the root of the teeth. Plot the graph between H vs Distance from the root. From the graph find the H_mean.
(b)	Three values of H found at three equidistance points (i.e. two ends and at the middle along with the height of the tooth). $H_{m e a n} = \frac{H_{1} + 4 H_{2} + H_{3}}{6}$
(c)	$H_{m e a n} = H_{\frac{1}{3}}$ (H at 1/3 hight of the tooth from narrow end.
(d)	All of these

69.

Select the best option which defines Simpson's rule method for the calculation of MMF for teeth.

(a)	Find different H values for the different distances of teeth from the root of the teeth. Plot the graph between H vs Distance from the root. From the graph find the H_mean.
(b)	Three values of H found at three equidistance points (i.e. two ends and at the middle along with the height of the tooth). $H_{m e a n} = \frac{H_{1} + 4 H_{2} + H_{3}}{6}$
(c)	$H_{m e a n} = H_{\frac{1}{3}}$ (H at 1/3 hight of the tooth from narrow end.
(d)	All of these

70.

Select the best option which defines the (1/3)^rd Flux density method for the calculation of MMF for teeth.

(a)	Find different H values for the different distances of teeth from the root of the teeth. Plot the graph between H vs Distance from the root. From the graph find the H_mean.
(b)	Three values of H found at three equidistance points (i.e. two ends and at the middle along with the height of the tooth). $H_{m e a n} = \frac{H_{1} + 4 H_{2} + H_{3}}{6}$
(c)	$H_{m e a n} = H_{\frac{1}{3}}$ (H at 1/3 hight of the tooth from narrow end.
(d)	All of these

Showing 61 to 70 out of 84 Questions