You have been told everything you need but let me give it a try.
Badar said:
I think now i m getting this.
But can you make me visualize that low resistance corresponds to high load
As above all you need to know is in Ohm's Law.
A resistor is like a valve that controls the current flow.
Think of it like this. You hook a fire hose up to a fire plug (the mains). On the end of the hose is a valve (a resistor). The water want to flow from the fireplug to the street/drain which is a good analogy for electrical ground.
With the valve wide open there is little or no resistance and the valve allows all the water the hose can carry to escape (A large load
lots of water flow because the valve has little/no resistance).
With the valve half shut less water comes out because there is more resistance to flow ( A smaller load
less water flow due to greater resistance).
With the valve fully shut no water flows at all (very very high resistance results in no load
no water flow, as in the switch is off).
if so then how the A.C or any other appliances use this heavy current as it sis just passing through it and is not utilized.
You should understand from the above that an appliance (which is in effect on resistor) only allows the current that it actually uses to flow through it. Just like the valve on the fire-hose.