Questions regarding DC circuits

  • Context: Engineering 
  • Thread starter Thread starter R A V E N
  • Start date Start date
  • Tags Tags
    Circuits Dc
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
3 replies · 3K views
R A V E N
Messages
63
Reaction score
0
I have one confusing issue to resolve:

What is the resistance between points [tex]A[/tex] and [tex]B[/tex] in simple system illustrated in attachment?Wouldn`t be logical to assume that it is [tex]0[/tex],as current strives to flow through path with lowest possible resistance,if I understood it correctly?

Yes,I know that real transmission lines have some resistance,but in network anaylsis their resistance is considered to be equal to zero.
 

Attachments

  • ab.gif
    ab.gif
    985 bytes · Views: 505
Last edited:
Physics news on Phys.org
R A V E N said:
I have one confusing issue to resolve:

What is the resistance between points [tex]A[/tex] and [tex]B[/tex] in simple system illustrated in attachment?Wouldn`t be logical to assume that it is [tex]0[/tex],as current strives to flow through path with lowest possible resistance,if I understood it correctly?

Yes,I know that real transmission lines have some resistance,but in network anaylsis their resistance is considered to be equal to zero.


You have a short circuit so what ever the resistance of the wire connecting point A and B.

CS
 
Yeah, it's zero assuming everything's ideal. Mathematically even, you have a wire ([tex]R=0[/tex]) in parallel with a resistor ([tex]R=R_0[/tex]). Then the parallel combination is:

[tex]R_{eq} = \frac{1}{ \frac{1}{0} + \frac{1}{R_0} } = \frac{1}{\infty + \frac{1}{R_0}} = 0[/tex]

I should probably have put some limits in there to be mathematically correct, but you get the idea.
 
Thanks to both of you!