Final answer:
When opposite potentials in a circuit come into direct contact, it causes a direct short or short circuit, which is a low-resistance connection that can lead to significant heating and damage. The correct answer is O direct short.
Step-by-step explanation:
When opposite potentials in a circuit come into direct contact, it causes a direct short. A short circuit is an undesired low-resistance path across a voltage source, which can cause catastrophic failures in electrical systems. When insulation on wires is compromised, it can allow them to come into contact, resulting in a dramatically reduced resistance.
According to the formula P = V²/r (where P is power, V is voltage, and r is resistance), if the resistance is very low, the power dissipated in the form of heat can be extremely high, potentially causing the wires to melt or burn.
An example involves a household electrical system with a potential of 120 V; a short circuit with a resistance of 0.100 ohms would result in a power of 144 kW, far exceeding the power usage of typical household appliances and likely leading to melting or ignition of surrounding materials.