Gopika asked:

What is the basic difference between short circuiting & overloading?
Why is area considered as both scalar and vector quantity?

Ans:

Short circuiting

As such the words suggest, the circuit becomes shorter. If there is a failure in insulation or some other means by which the two wires (phase and neutral) comes into electrical contact, the circuit gets shortened as the current always chooses the path which has got least resistance. Since the resistance of the shorted circuit is less a heavy current flows.

Overloading

In house hold circuiting we are using parallel combination of the different appliances. Every instrument is connected in parallel to the supply. Whenever a new apparatus is switched on, it draws more current. If the current drawn by all the devices connected in a circuit is more than the maximum current rating for the given circuit, the condition is called overloading.