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.
a cage rotor consists of
laminated soft iron with copper or iron end rings
laminated soft iron core containing longitudinal copper or iron bars which are capped at each end via a shorting plate.
laminated silica steel core containing longitudinal copper bars shorted at one end only
laminated soft iron core with three phase star connected windings and slip rings,
rotor eddy currents are :-
large currents created in the laminated iron core .
large currents induced in copper or iron bars that are shorted at each end
currents caused by hysteresis loops in soft iron
found in ox bow lakes
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
the rotor in an induction motor can :-
reach synchronous speed quickly
reach rotor speed slowly
always rotate close to the synchronous speed
can never reach synchronous speed
rotation is produced in a rotor due to :
Flemings left hand rule
Flemings right hand rule
Faradays laws of mutual induction
Lenzes Law
The rotating part of a motor is
Stator
Rotor
Frame
Bearing
An electrical motor changes electrical energy to ______________ energy
Mechanical
Chemical
Physical
Potential
The principle of operation of three phase induction motor is similar to........
Synchronous motor
Repulsion start induction motor
transformer with a shorted secondary
capacitor start induction run motor.
If slip value is less than 1, it means, the machine is
motoring
Braking
Generating
Transferring
Slip of Induction Machine can be written as
Stator Cu loss/Rotor output
Rotor Power/Rotor input
Rotor Cu loss/Rotor input
Rotor Cu loss/Rotor output
What creates a rotating magnetic field in an induction motor?
The angular speed of the motor
Three phase current flowing in the rotor
Three phase current flowing in the stator
A single phase current flowing in both the rotor and the stator
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
