DC vs Step Change Current: Which Induces More Current?

AI Thread Summary
A DC current of 50V and 10A does not induce voltage in an inductor since the change in current (δI/δt) is zero. In contrast, a step change from 1mA to 3mA represents a time-varying current, which can induce a voltage according to Faraday's law of electromagnetic induction. The discussion emphasizes the importance of understanding the difference between steady-state DC and time-varying currents in inducing electromotive forces. The arrangement of conductors, such as parallel wires, also plays a crucial role in the interaction between the currents. Ultimately, the step change current is more effective at inducing current due to its time-varying nature.
liam1992
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Which can induce more current in a conductor, a DC current of 50V 10A or a step change from 1mA to 3mA?

I thought that in a DC circuit the inductor would not induce a voltage as V=L(δI/δt) where (δI/δt) is 0 for a DC circuit. But then some websites that I have looked at say differently so I'm a bit confused. The question doesn't give me enough information to use any of the equations that I have been taught so could you please tell me how to sove this problem. Thank you.
 
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Try Farady's and Ampere's laws ...
 


rude man said:
Try Farady's and Ampere's laws ...

Surely I don't have enough information to apply either of these laws though
 


The arrangement is of two parallel wires, is it? When the current in one of them matches what you describe, what happens in the other wire? Is that the question?
 


NascentOxygen said:
The arrangement is of two parallel wires, is it? When the current in one of them matches what you describe, what happens in the other wire? Is that the question?

I don't know, that statement is all that I was given so I don't know if I am supposed to make assumptions or not.
 


NascentOxygen said:
The arrangement is of two parallel wires, is it? When the current in one of them matches what you describe, what happens in the other wire? Is that the question?

liam1992 said:
I don't know, that statement is all that I was given so I don't know if I am supposed to make assumptions or not.

Well, with such scanty specifications, maybe you are allowed to wave one wire furiously around in the vicinity of the other https://www.physicsforums.com/images/icons/icon5.gif
 
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liam1992 said:
Surely I don't have enough information to apply either of these laws though

Ah, but you do!
 


rude man said:
Ah, but you do!

I thought you needed the length of the wire and radius to work out the magnetic field strength and things
 


liam1992 said:
I thought you needed the length of the wire and radius to work out the magnetic field strength and things

Not in this case.

Hint: one's a dc current, one is time-varying. Then think about Messrs. Faraday and Ampere.
 

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