Why is voltage 0 in a short circuit?

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SUMMARY

In a short circuit, the resistance (R) approaches zero, leading to an undefined situation where current (I) theoretically approaches infinity. However, the voltage (U) is zero because a short circuit occurs when two points in a circuit have the same electrical potential. This means there is no potential difference to drive current, resulting in a voltage of zero. In practical scenarios, current is limited by circuit components, preventing infinite current flow.

PREREQUISITES
  • Understanding of Ohm's Law (U=IR)
  • Basic knowledge of electrical circuits and components
  • Familiarity with electrical potential and voltage concepts
  • Awareness of real-world limitations in circuit behavior
NEXT STEPS
  • Study the implications of short circuits in electrical safety
  • Learn about circuit protection devices like fuses and circuit breakers
  • Explore the concept of electrical potential difference in various circuit configurations
  • Investigate real-world current limiting factors in electrical circuits
USEFUL FOR

Electrical engineers, physics students, and anyone interested in understanding circuit behavior and safety in electrical systems.

alexmath
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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?
 
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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.
 
alexmath said:
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.
 

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