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Why the efficiency of induction motor is less than that of transformer?
ShipuBishwas
Because, the losses of IM is more due to the contribution of friction losses at shaft bearings and wind age losses in rotor air gap, this reduces the efficiency of the equipment, Since transforms is a static equipment zero mechanical loss so efficiency of the equipments in high .
Wiki User
∙ 11y ago
Wiki User
∙ 11y agoinduction motor has mechanical losses whereas transformer is a static device the mechanical losses are absent hence induction motor has less efficiency
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Explains why a 3-phase induction motor develops no torque when running at synchronous speed?
When rotor speed becomes equal to Synchronous speed in an induction motor, it means that the slip is zero. Which means that there is no cutting of magnetic lines by rotor bars and hence no torque is generated. To generate Torque, rotor speed should always be less than the synchronous speed. That is why, you must have seen in your dailty life that all induction motors are rated below 3000 RPM(sync speed for a 2 pole machine). Sync speed (Ns) = 120f/P
Does the input and output frequency of the transformer is the same?
For an 'ideal' transformer operating at full load, the answer is yes. But, 'real' transformers are a little less than 100% efficient so, in practice, the input power will slightly exceed the output power. In most circumstances, for the purpose of calculating primary and secondary currents, we can assume 100% efficiency.
What is the relationship between frequency and the size of a transformer?
Basically the characteristics of a transformer depends on the impedance(resistance) and on the coupling of its primary and secondary coils. The impedance of a coil depends on the frequency, as the frequency increases you need less volume of iron core and less number of turns in the coil for a given impedance, then reducing the size of the transformer.
How much energy is used by a transformer?
An efficient transformer will convert more than 99% of the input energy into output energy, therefore wasting less than 1%.
Why is it impossible for induction motor to operate at synchronous speed?
Torque is produced because the rotating magnetic field, set up by the stator windings, cut and induce voltages into the rotor bars. The fields set up by the resulting rotor-bar currents then interact with the rotating field, causing the rotor to turn. If the rotor turns at the same speed as the rototing field, then its bars will not be cut by the field, there will be no induced voltages, no bar currents, and the torque will disappear.
Why less current increases in transformer than in induction motor when load is increase?
The current flowing through a transformer's secondary is the current drawn by the load, so it will be exactly the same as the current flowing through your induction motor -assuming that is the load. Don't really understand the point of your question!
Application of induction motor in industry?
Induction motor used in industries for variable speed machines . Induction motor has always lagging power factor. Less cost compared to syn. Motor.
What are the advantages of single phase induction motor?
the torque requirement of single phase induction motor is less,and it is use for low power applications upto 1 to 10 kw.like in fans,mixiers
A motor produces less mechanical energy than the energy it uses because the motor what?
Yes this is what we call efficiency of the motor. We give 100 but the motor in turn gives 40, so its efficiency is 40%
Difference between induction motor and induction generator?
in case of induction motor the rotor speed is less than synchronous speed giving positive slip but in case of generator the rptor speed is greater than synchronous speed giving negative slip.......
Why are transformer more efficient that rotating electric machines?
Because the electrical parts of a transformer do not move / rotate.
Can 3 phase induction motor work when one phase is failed?
yes the motor will rotate but less then the rated speed and more heat will be desipated
What if you have no backpressure on a motor?
the motor will run with full efficiency as designed. No resistance means less energy expenditure. motor doesn't have to compensate for in line obstruction.
What is type of DC and ac motors?
DC Motor :- SHUNT MOTOR, Series Motor, Compund Motor, ( mainly used in traction system only. as there performanace is very poor & DC supply is not available easily so there uses is less then AC motors,) AC Motor:- Induction Motor ( Slip ring Type, squrrile cage Induction motor) Syncronous Motor.
Why induction motor speed is always less then synchronous speed?
induction motor never runs at synchronous speed, if it does so there would not be any relative speed between stator flux and rotor and no emf will induce in rotor and we can not apply motor principle as we need current carrying conductor in magnetic field.
What is the motor that is the most common type of motor system used on hermetically sealed units?
most probably it should be a squirrel cage induction motor since it needs very less maintenance.however it also depends on the application.
Why are distribution transformers frequently designed to develop maximum efficiency at loads that are somewhat lower than rated value?
It is always desirable to run any equipment or device at maximum efficiency for that matter, not only the power transformer. Power transformer maximum efficiency occurs when copper loss is equal to iron loss. (or no load loss equals to load loss). This does not necessariliy mean that maximum efficiency occurs at maximum or full load. Generally the maximum efficiency occurs at relatively less than full load of the transformer.
