Home Preparation for National Talent Search Examination (NTSE)/ Olympiad
Chapter : 2. Magnetic Effect of Current
Earthing , Overloading & Short Circuits The current exceeds the limit under two situations. (i) over–loading (ii) short–circuiting They are discussed ahead. Over–Loading : When high powered electric appliances like refrigerator, airconditioner and electric iron are switched on simultaneously, total current through main wire may exceed the tolerance limit causing damage and fire. This situation causes over–loading. Short–Circuiting : Due to long use wear and tear or defective insulating material, the live and the neutral wires may become bare at some points and come in direct contact. Due to zero resistance, a large current is produced and a huge sparking is caused at the point of contact. It may cause damages and fire. This situation is called short–circuiting.