WorksheetsThree Phase Induction Motor
Total questions: 15
Worksheet time: 8mins
a rotating magnetic field is created by :
applying three phase waveforms to rotor winding placed 120 degrees apart.
applying three phase line voltages to stator winding via sliprings
applying three phase line voltages to red yellow and blue stator windings.
applying three phase phase voltages to a delta connected load.
slip is defined as :
the difference between synchronous speed and rotor speed
the difference between rotor speed and synchronous speed
synchronous speed - rotor speed / rotor speed
(rotor speed - synchronous speed ) / synchronous speed
If slip value is less than 1, it means, the machine is
motoring
Braking
Generating
Transferring
3-phase induction motor is a self-starting machine
True
False
What happens when Induction motor runs at synchronous speed, motor will
Burn
Stop
Delivers Real Power
Delivers reactive power
The symbol shown in the figure represents:
single phase motor
Y- connected induction motor
∆- connected induction motor
Three phase transformer.
The main parts of the Induction Motor are what?
Stator, rotor, terminal box
Enclosure, rotor, windings
Enclosure, stator, rotor
Stator, rotor, power chord
Which motor connection would this be in a terminal box?
(a)
The single phase induction motor does not produce a rotating magnetic field
True
False
I don't know
Maybe
The method which can be used for the speed control of induction motor from stator side is
V / f control
Controlling number of stator poles to control Ns
Adding rheostats in stator circuit
All of these
Three-phase induction motor is mainly suitable for which of the following application
For running different machine tools where several speeds are required
For running paper machine requiring exact speed control
For running electric vehicles
For running rolling mills needing exact speed control
The speed of a 50 Hz 3 Phase Induction Motor with 8 poles running with 2% slip is:
367.5 RPM
2940 RPM
735 RPM
15 RPM
How many poles does a 3 Phase Induction Motor have if it is supplied at 60 Hz, has a slip of 5% and runs at a speed of 1140 RPM
2
3
4
6
If a 3 Phase Induction Motor has 4 poles and is connected to a 60 Hz supply it has a synchronous speed of:
1500 RPM
750 RPM
900 RPM
1800 RPM
