Answer / sindhejs

Since the suplly is of 3 phase sinusoidal in nature, flux
produced due to htis in the stator is of alternating in
nature.This flux is cut by the stationary conductor on the
rotor, thus eddy currents are induced in the rotor circuit
by Lenz's law.To overcome force produced by these currents
and induced flux the rotor starts rotating in the direction
of flux.

Answer / surya

in indction motor, motor windings alos plays a very
important role. these are also placed 120 degree apart. so
when you apply 3 phase supply, it forms a magnetic pole in
the stator. as the 3 phase supply is sinusoidal, the formed
magnetic pole starts rotation in one direction,that is the
synchronous speed of motor. as per farday's law of
electromagnetic induction, when a conductior cuts the
changing magnetic field and it's circuit is closed, an emf
is induced in it. so an emf causes curent to flow which
experiences force on conductor. rotor starts rotating.
for better understanding make a diagram of 3 phase
windings 120 degree physically apart. r-y-b and simulate
the 3 ph supply. hope this is informative.

Answer / manav

The three phase windings of stator of a 3-ph ind. motor are
placed 120 deg space displaced.
Also the supply given to these is a 3-ph supply with time
lag of 120 deg b/w each phase.
thus, the expressions for mmf of each phase at any instant
at an angular position $ in air gap is given by:

Fr=Fm*cos(wt)*cos($)
Fy=Fm*cos(wt-120)*cos($-120)
Fb=Fm*cos(wt+120)*cos($+120)

adding all these three gives the resultant:

F=Fr+Fy+Fb= (3/2)*Fm*cos($-wt)

This is like a travelling wave [F=Fm*cos(kx-wt)] that
rotates with speed w.

Answer / govind

in ac motor is only stator & rotor, then how magnetic field
is rotate around the armeture

Answer / dinesh verma

in indction motor, motor windings also plays a very
important role. these are also placed 120 degree apart. so
when you apply 3 phase supply, it forms a magnetic pole in
the stator. as the 3 phase supply is sinusoidal, the formed
magnetic pole starts rotation in one direction.

what is earth fault relay 64T, why it is used in main Incomer and neutral CT of Transformer.

0 Answers  

diffance between eletrical and eletronics?

3 Answers  

what are the applications of TIG welding

0 Answers  

Which motor has high Staring current A. Series DC motor, B.Induction motor c.Synchronous motor D.DC Shunt Motor

4 Answers   CCP,

what is the difference between active power and reactive power and apparant power in practical as well as theoritical

0 Answers  

1.Can we use 6.6/11KV 300sq mm xlpe 3core cable for LT use (415 Volt). 2. If we use it for LT then what is the current rating

0 Answers  

definition of fault level in powersystems?

4 Answers  

How can calculate rotor temperature of the alternator? and is there any method to calculate that

1 Answers  

what is voltage rise and voltage drop?

8 Answers   HP, jetking, TCS,

what is the difference between the HT Cable and LT Cable ?

28 Answers   Intergulf, Prabhat Cables,

what is corona effect?

39 Answers   ABB, Genco, Wipro,

WHICH TYPE OF TRANSFORMER USED IN SWITCHYARD IN POWER PLANT?

15 Answers   GE, Lanco, NTPC,