Why voltage in a short circuit is 0?

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
3 replies · 2K views
alexmath
Messages
35
Reaction score
0
Why voltage in a short circuit is 0?

I=U/R , R goes to 0, I goes to infinity => U=IR= 0 times infinity, i don't get it, why 0 "wins" here? Thank you!
 
Physics news on Phys.org
alexmath said:
Why voltage in a short circuit is 0?

I=U/R , R goes to 0, I goes to infinity => U=IR= 0 times infinity, i don't get it, why 0 "wins" here? Thank you!

R goes to zero correct. So U must be zero so that current is finite. 1/0 is infinite 0/0 is finite.
 
In real circuits, I is always limited in some way (by the power supply, for example). Usually this is more important than the tiny resistance of wires.
 
Voltage is a measure of how much energy is needed to move charge from one point to another.
If the resistance is zero then no energy is needed.
Understanding of physics is the explanation, don't get tied up multiplying and dividing zeros and infinities.