Why Binary no.taken 0,1 it may be something else of two digit but why 0,1???

Answer 1

You count from 0 onwards, you will realise.
However, after base 10,base 11 wouldn't want a "10" to confuse with a "1""0", so they use alphabets.
Then symbols, then etc.

Answer 2

its just easier to represent on and off with a 0 and 1.

Answer 3

it is 0 and 1 cause of the electricity. Your ele tricity inside a machine is flowing. think of a processor as a big stack of switches that can be either on or off. why do you want to choose another numbers to represent No-electricity as 0? 0 is null, it is a big" NO".
1 actually just means "something", "on".
this is as simple as it gets