短路點解/點樣會增加電流??

"short circuit"(短路) means the reistance of a circuit is greatly reduced. According to Ohm's Law, the current flows through a circuit is inversely proportional to its resistance. If the circuit resistance is greatly reduced, a large current will flow through the circuit.
This large current flow would cause an heating effect. As the heat produced is somewhat proportional to the square of the current, a large current produces a tremendous amount of heat in the circuit. This of course could could cause fire to break out.

短路是指在正常電路中電勢不同的兩點不正確地直接碰接或被阻抗（或電阻）非常小的導體接通時的情況。短路時電流強度很大，往往會損壞電力設備或引起火災。