why are MCB's most commonly used in place of fuses?
MCBs are most commonly used in place of fuses, because it is easier to turn on an MCB, when it is tripped. If a fuse is blown away, we have to take the fuse from the socket and replace the fuse wire. Comparing to this, turning on an MCB is an easy process. Moreover, MCBs provide more safety than fuses. A fuse wire of wrong size will not protect the appliance or human beings. So, care must be taken while changing the fuse wire.