how a transformer works??

[sachinmachin]

if this question were to come up tommorow, would you discuss how it steps up/steps down voltage?? or would you just discuss the changing magnetic field, changing flux, emf induced etc.??

[dejan91]

I think it would depend on the question. For something like 'How does a transformer work?' I think it would be enough to write something like this:

A transformer works on the principal of electromagnetic induction. A changing magnetic field in the primary coil induced a proportionally changing magnetic field in a soft iron core. This soft iron core is used to transfer the magnetic field between the primary and secondary coils. As such, a change in magnetic flux is created though the secondary coil.Thus, as can be seen by the formula EMF = ....... , a voltage is produced due to this change in flux.

Not sure if you need to mention step-up/step-down because a transformer can have an equal number of primary coils as it does secondary coils (even though that's kinda pointless). However, you're explaining how it works. But I'd probably mention it somewhere just to be safe anyway.

[NE2000]

With the whole step-up/step-down coil thing. I know at the secondary you can explain how the number of coils produces a proportional emf using Faraday's law, but how exactly does a step-down transformer work? How can the voltage be reduced if the number of coils in the secondary are less than that in the primary?

I'm still curious about this even if it's not going to be tested

[naved_s9994]

A changing current in the primary coil produces a changing magnetic field in the iron core(1), which produces a changing magnetic flux inside the secondary coil (1), which induces a changing voltage across the secondary coil. (1) – Also you write the EMF Equation! 

...and you will get 3/3 marks

[/0]

I might do







Along with what naved said