In electrical motors what is the slip?

Slip

Slip, , is defined as the difference between synchronous speed and operating speed, at the same frequency, expressed in rpm or in percent or ratio of synchronous speed. Thus

where  is stator electrical speed,  is rotor mechanical speed. Slip, which varies from zero at synchronous speed and1 when the rotor is at rest, determines the motor's torque. 

The slip in an electrical motor is the differnce betrween the synchronous speed (ns)and the rotor speed (nr) ,

%slip=[ (ns-nr)/(nr)]*100

slip is the diffrence between rotor speed and synchronous speed

it is the start up ramp time

Slip can be defined as "the speed by which the stator field moves ahead of the rotor speed.". Normally denoted by the variable"s". it is a unit less value, expressed in percentage.

slip is a ratio between shaft rotation speed and synchronous magnetic field speed..

slip  change with voltage, frequency,rotor impedance and inductive reactance..

With Regards

Niraj Mani

Slip is the ration of difference of synchonous speed and rotor speed to synchronous speed.

Slip= Ns-Nr/Ns

The difference between Synchronous Speed & Rotating speed is called Slip

Difference between rotor speed and synchronous speed( (synchronous speed -rotor speed)/rotor speed)

I'm agree with you all 

 The SLIP: is the ratio between (the difference between the Stator Speed "Synchronous Speed" and the Rotor speed) TO the stator speed "Synchronous Speed".

S=(Stator Speed - Rotor Speed) / Stator Speed