During a short circuit, the resistance in the circuit becomes extremely low but does not typically reach absolute zero. This happens because the current flow increases significantly, as the electrical path faces minimal opposition.
Why Does Resistance Drop in a Short Circuit?
Short Circuit Path:
A short circuit occurs when an unintended low-resistance path bypasses the normal circuit. This direct connection allows current to flow almost unimpeded.
Ohm’s Law:
According to Ohm’s Law:
| V=I×R |
Where:
- V is voltage,
- I is current,
- R is resistance.
In a short circuit, the resistance R approaches zero, which causes the current III to increase drastically for any given voltage VVV.
Does Resistance Become Exactly Zero?
While the resistance becomes very small, it is never exactly zero due to:
- Wire Resistance:
Even conductors, like copper wires, have tiny inherent resistance. - Practical Factors:
Imperfections, material properties, and connection points always contribute to minimal resistance.
However, in ideal conditions (like theoretical circuits), resistance could approach zero during a short circuit.
Effects of Low Resistance During Short Circuits
- High Current Flow: The sharp drop in resistance allows an extremely large current to flow through the circuit.
- Overheating: Excessive current generates heat, potentially damaging components and wires.
- Electrical Hazards: Prolonged short circuits can cause fires or explosions if not quickly mitigated.
Real-Life Example of Short Circuit
Consider a situation where the two terminals of a battery are directly connected without any load or resistance in between:
- The current flow will increase dramatically since there is very little resistance.
- The wire may overheat and melt due to the large current passing through it.
Explore More:
- How Does an Electric Motor Work?
- Why is the Bulb of a Thermometer Made of Thin Glass?
- What is a Solar Cooker?
- Why is Force Said to Be the Rate of Change of Momentum and Not Just Change in Momentum?
- How Do You Identify if a Lens Has a Positive or Negative Focal Length?
Conclusion
In a short circuit, the resistance value drops to an extremely low level, approaching zero, but does not become exactly zero due to practical limitations like wire resistance. This minimal resistance allows for an uncontrolled increase in current, which can lead to significant hazards if not properly managed.
