61
Frog leg winding is
Answer: Combined lap and wave windings on a single rotor
Questions
62
In a compound dc motor, the shunt field winding as compared to series winding will have
Answer: More turns of smaller diameter
64
The direction of rotation of a dc motor can be reversed by reversing the connection to
Answer: Armature
65
When an electric traian is moving down a hill the dc motor acts as
Answer: Dc series generator
66
If the armature current of a dc motor is increased keeping the field flux constant, then the developed torque
Answer: Increases proportionately
67
The armature current drawn by a dc motor is proportional to
Answer: Torque required
68
A dc shunt motor is driving a constant torque load with rated excitation. If the field current is reduced to half, then the speed of the motor will become
Answer: Slightly less than double
70
Armature voltage control is suitable if d.c. machine is driven at constant
Answer: Torque
71
In all electric machines, basic action taking place is
Answer: Both (a) and (b)
73
All machines have the structure such that
Answer: Armature is rotating and field is fixed
74
Maximum number of brushes which can be used in a machine is
Answer: Number of poles in the machine or 2
76
If field of d.c. shunt motor is opened, then
Answer: Speed of motor will be high
77
Which of the following motors has high starting torque?
Answer: D.C. series motor
79
A dc series motor is running with a diverter connected across its field winding. If the diverter resistance is increased, then the speed of the motor
Answer: Decreases/increase
80
A dc series motor is running at rated speed. If a resistance is placed in series, the speed of the motor
Answer: Decreases
