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

Showing 51 to 60 out of 84 Questions

51.

Which of the following statement/s is/are justified Field form factor?

(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

52.

Which of the following statement/s is/are justified Gap contraction factor for the slot?

(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

53.

Which of the following statement/s is/are justified Gap contraction factor for the ducts?

(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

54.

Field form factor K_f =

(a)	$= \frac{a v e r a g e f l u x d e n s i t y o v e r t h e p o l e p i t c h}{m a x i m u n m f l u x d e n s i t y i n t h e a i r g a p}$
(b)	$= \frac{R e l u c \tan c e o f a i r g a p w i t h s l o t t e d a r m a t u r e}{R e l u c \tan c e o f a i r g a p w i t h s m o o t h a r m a t u r e}$
(c)	$= \frac{R e l u c \tan c e o f a i r g a p w i t h d u c t s}{R e l u c \tan c e o f a i r g a p w i t h o u t d u c t s r}$
(d)	$= \frac{c o n c e n t r a d e d w i n d i n g}{d i s t r i b u t e d w i n d i n g}$

55.

Gap contraction factor for the slot K_gs =

(a)	$= \frac{a v e r a g e f l u x d e n s i t y o v e r t h e p o l e p i t c h}{m a x i m u n m f l u x d e n s i t y i n t h e a i r g a p}$
(b)	$= \frac{R e l u c \tan c e o f a i r g a p w i t h s l o t t e d a r m a t u r e}{R e l u c \tan c e o f a i r g a p w i t h s m o o t h a r m a t u r e}$
(c)	$= \frac{R e l u c \tan c e o f a i r g a p w i t h d u c t s}{R e l u c \tan c e o f a i r g a p w i t h o u t d u c t s r}$
(d)	$= \frac{c o n c e n t r a d e d w i n d i n g}{d i s t r i b u t e d w i n d i n g}$

56.

Gap contraction factor for the ducts K_gd =

(a)	$= \frac{a v e r a g e f l u x d e n s i t y o v e r t h e p o l e p i t c h}{m a x i m u n m f l u x d e n s i t y i n t h e a i r g a p}$
(b)	$= \frac{R e l u c \tan c e o f a i r g a p w i t h s l o t t e d a r m a t u r e}{R e l u c \tan c e o f a i r g a p w i t h s m o o t h a r m a t u r e}$
(c)	$= \frac{R e l u c \tan c e o f a i r g a p w i t h d u c t s}{R e l u c \tan c e o f a i r g a p w i t h o u t d u c t s r}$
(d)	$= \frac{c o n c e n t r a d e d w i n d i n g}{d i s t r i b u t e d w i n d i n g}$

57.

Field form factor K_f =

58.

Gap contraction factor for the slot K_gs =

59.

Gap contraction factor for the ducts K_gd =

60.

Calculate field form factor (K_f) from the following data:

no. of pole = 2

diameter of the core = 0.13 m

Pole are = 0.18 m

Showing 51 to 60 out of 84 Questions