Why electricity in India is in the multiples of 11 like 11kv, 22kv, 33kv ?

 Transformer Induced voltage equation contains 4.44 factor.

               

                       E=4.44*f*T*phi

E -Induced emf per phase

T -number of turns

f -frequency

phi -maximum flux per pole

From the equation we see that E is proportional to 4.4 and it is in turn multiple of 11.So always transmission voltage is multiple of 11.