CS/B.Tech(PWE/NEW)/SEM-4/PWE-401/2013
2013
ELECTRICAL MACHINE
Time Allotted : 3 Hours Full Marks : 70
The figures in the margin indicate full marks.
Candidates are required to give their answers in their own words
as far as practicable.
GROUP – A
( Multiple Choice Type Questions )
1. Choose the correct alternatives for any ten of the following :
10x1 = 10
i) The armature control scheme for the speed control of
dc motor is used for
a) controlling the speed above the base speed
b) controlling the speed below the base speed
c) both (a) and (b)
d) none of these.
ii) The speed-torque characteristic of a d.c. series motor is
a) a straight line passing through origin
b) a straight line having negative slope
c) hyperbolic in nature
d) parabolic in nature
iii) Which type of d.c. motor is suitable for traction drive ?
a) cumulatively compound d.c. motor
b) differentially compound d.c. motor
c) d.c. shunt motor
d) d.c. series motor.
iv) If the speed of a d.c. shunt motor is increased above
the base speed, then its counter emf
a) increases
b) decreases
c) remains unchanged
d) first increases then decreases.
v) In a d.c. series generator, the terminal voltage with
incease in load will
a) decrease
b) increase gradually and then stay at rated voltage
c) increase to rated voltage and then may decrease
d) remain nearly constant.
