What is the Difference between 380 and 440 v?

b/c if voltage decreases therefore the current is increases
due to p=v*i & hence if current is increases therefore the
magnetic flux will also increases & hence there is good
magnetic strength will occurs

It is the requirement of the machine.we can either operate
in 440 or 220 or even in 110 volts.The voltage depends upon
the motor,circuit and other loads related with the machine.