These bumps are depth markers. Nails pre installed Handy Boxes always come with two nails on them. The nails make it faster to install the box. You will simply hold the box in the desired install location, check the depth markers and nail the nails in.

To attach the wires to the new outlet, use a pair of needle-nose pliers or a wire stripper to make a hook with the wire, loop it around the appropriately colored screw on the receptacle, then.

Considering p duplex receptacle, if I break the tab, can both receptacles supply 20 amps? The outlet configuration – the physical design of the holes – determines what can be plugged into it. As both “halves” are the same configuration, either one can provide 20 amps. You should note, however, that trying to pull 40 amps from one 20 amp circuit will absolutely trip the breaker.

In wiring a switched half-hot outlet that gets Its power from the outlet box if the end of the white neutral wire is capped in the switch box, why can’t the end of that wire also be capped in the receptacle box? It is serving no purpose in the circuit. I can only speculate as to why the writers of that rule included it, but without a neutral in the switch box, there is no legal or safe method starting a new circuit there.