CS/B.Tech(EE/PWE(O))/SEM-4/EE-401/2012
2012
ELECTRICAL MACHINES-I
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) In a DC series motor torque is approximately
proportional to
a) Ia2 b) Ia
c) V2 d) V.
ii) Which type of motor is used for lifting purpose in
crane ?
a) Shunt motor b) Series motor
c) Induction motor d) None of these.
iii) A commutator in dc machines can
a) convert dc to ac
b) provide full wave rectification
c) convert ac to dc
d) both (b) & (c).
iv) If the field of a dc shunt motor gets opened while the
motor is running, then
a) speed of the motor will reduced
b) motor will attain dangerously high speed
c) armature current will drop
d) armature will oscillate about original speed as the
mean speed.