During short-circuiting, the current flowing in the electrical circuit

During short-circuiting, the current in an electrical circuit increases instantaneously and abruptly [1]. This phenomenon occurs when the live wire and neutral wire come into direct contact, often due to damaged insulation or appliance faults [1]. According to Ohm's law, current is inversely proportional to resistance [2]. In a short circuit, the resistance becomes negligible or very small, effectively approaching zero. Consequently, the current flow is no longer restrained by the normal load resistance, leading to a massive surge that can be thousands of times larger than the rated current. This uncontrolled flow of high electric current generates significant Joule heating, which is why safety devices like fuses are employed to melt and break the circuit to prevent fire or damage [1]. While protective devices eventually reduce or stop the current, the immediate physical response during the fault is a rapid, substantial increase [1].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 12: Magnetic Effects of Electric Current > 12.4 DOMESTIC ELECTRIC CIRCUITS > p. 205
2. [2] Science , class X (NCERT 2025 ed.) > Chapter 11: Electricity > I = V/R (11.7) > p. 176