basics of electrical supply

[ante1]

Hi aakaash,

It sounds disastrous to me; you might get away with it if it was DC if you had a resistor in line with it but AC…no way! If the frequency is of sync, high current flows and something will blow! Maybe your inverter has some kind of sync for 50 or 60 Hz and voltage correction in it? ???

 

[audioguru2]

You never connect the output of an inverter to the mains. As Ante says, the mains would blow it up! You plug a load like some lights into its output. If it powered your whole neighbourhood or city then it would be very overloaded!
Maybe you are thinking about a Un-interruptable Power Supply (UPS) that has a relay inside that switches the load from the mains to the output of an inverter when the mains fails. Then when the mains comes back on, the relay switches the load back to the mains.
The mains might be used to charge the battery in an inverter.