Why is voltage 0 in a short circuit?

[alexmath]

We know that U=IR (ohm's law)
in a short circuit, R goes to 0, I goes to infinity so the voltage goes to 0*∞ which is undefined!
Why voltage is 0?

 

[f95toli]

Because in a short circuit, the potential difference is zero...

Remember that voltage is the the difference between the potentials of two points, and a short circuit is -by definition- the situation where the two points have exactly the same potential.

 

[phinds]

We know that U=IR (ohm's law)
in a short circuit, R goes to 0, I goes to infinity so the voltage goes to 0*∞ which is undefined!
Why voltage is 0?

Nothing goes to infinity in reality, just in idea circuits. In real circuits the current is limited and/or something burns up and the circuit opens.