Is a transformer following ohm's law?

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Discussion Overview

The discussion centers around whether a transformer adheres to Ohm's law, particularly in the context of voltage and current relationships in transformers compared to resistive loads. It explores the application of Ohm's law to transformers and the nature of electrical behavior in these devices.

Discussion Character

  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant asserts that a transformer does not obey Ohm's law because an increase in voltage leads to a decrease in current.
  • Another participant argues that Ohm's law is being misapplied, explaining that in an ideal transformer, voltage and current relationships can still be consistent with Ohm's law when considering the primary and secondary circuits separately.
  • It is noted that Ohm's law applies to resistive loads, and a transformer itself is not considered a load.
  • Some participants emphasize that Ohm's law should be applied to both the primary and secondary circuits of a transformer independently, rather than to the transformer as a whole.

Areas of Agreement / Disagreement

Participants express differing views on the application of Ohm's law to transformers, with no consensus reached on whether transformers can be said to obey Ohm's law in the same way as resistive loads.

Contextual Notes

Some limitations in the discussion include potential misunderstandings of how Ohm's law applies to different components in electrical circuits, and the distinction between Ohmic and non-Ohmic devices.

srishankar18
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According to ohm's law voltage is directly proportional to current that is if voltage get increased current also should get increased but in a transformer if voltage get increased current get decreased.

so, Is a transformer is obeying ohm's law or not
 
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You are not applying ohms law to the transformer correctly when stated the way you have. If you apply 100 volts to a 10:1 transformer you will end up with 10 volts out. If you put a 10 ohm resistor on the secondary you will have one ampere passing through the resistor. In an ideal transformer the 100 volt source will be sourcing .1 amps. Increase the primary voltage by a factor of 2 and the secondary voltage will increase by the same. The amps in both windings will increase by a factor of 2 as well. Ohms law has not been violated.
 
To put it another way, Ohms law is for determining the behavior of electricity through a load (a resistor). A transformer by itself is not a load.

We see people make this mistake a lot (that's 3 times in 3 days) and I don't know why...
 
Yep. Remember that Ohm's law only applies for Ohmic devices (which obey Ohm's law and hence named thus).

(Seriously, I'm not trying to be smart or patronising here.)
 
You apply Ohms law separately to the primary circuit and to the secondary circuit of a transformer. You do not use Ohms law to learn how the primary induces current in the secondary.
 
Thanks

Thanks a lot to every body who had taken care for replying this thread.

I've got some information from your answers.

Thank you ...:smile:
 

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