Question

is efficiency of transformer is greater than electrical machine and why?

Answer 1

Yes,efficiency of t/f is high.

To transmit power to long distances the losses in the transmission line should be less.

overall losses in transmission should be low.

and at both ends of transmission line we are having transformers for purpose of stepping up and down of voltages.

because transformer having less leakages as the core is made up of crgo steel and type of winding connections eleminates major harmonics.Main point to notice that "manufacturers design the transformers nearer to ideal conditions" which makes transformers to work at high efficiencies.

ideal conditions:1.zero losses 2.infinite permeability (i.e.,crgo steel is having high permeability)

3.resistances of t/f wdng is zero 4.Magnetization curve of t/f is linear

Answer 2

A transformer is an electrical machine.

I guess the question would be: Why a transformer is more efficient compared to an electric motor?

A transformer is a static electrical machine. Since there are no mechanical moving parts, hence less wear and tear and less friction and windage losses.

However, in a practical case, a transformer has magnetic and copper losses similar to an electric motor.

Answer 3

The efficiency of transformer is Greater than electrical Machine because there is no rotational losses in transformer and there is no air gap losses in transformer so losses is less in transformer compare to electrical machine so efficiency is higher in case of transformer.