Help for electrical transformer?

[neduet]

Hello friends:

I need answer of my question please

Q.1 In electrical transformer polarities must be same or not

Q.2 if transformer under normal condition load is also normal. Is there power of input feed equal to power output? (My teacher said input power = to output power)

Q.3 Must careful things to parallel transformer or transformer can be operated in series if yes. Then why?

thank you very much ...

 

[davenn]

Hello friends:

I need answer of my question please

Q.1 In electrical transformer polarities must be same or not

are you referring to voltage polarities ? a Transformer operates with an AC Voltage
its polarity is constantly cycling

Q.2 if transformer under normal condition load is also normal. Is there power of input feed equal to power output? (My teacher said input power = to output power)

yes almost ... minus losses in the transformer (eddy currents etc that cause heating), nothing is perfect

Q.3 Must careful things to parallel transformer or transformer can be operated in series if yes. Then why?
thank you very much ...

I think you are asking abut operating transformers in series or parallel ??

you wouldn't normally operate them in parallel, as in parallelling the output (secondary) windings... because of the windings unlikely to be exactly the same, there will be an imbalance between load sharing of the windings

series connection of output (secondary windings) done all the time, multi-tap transformers are used for producing multiple output voltages

hopefully that helped :)

Dave