A duplex outlet is 115vac.
Looking at a duplex receptacle the right smaller slot is hot, the left larger slot is neutral and the u ground is ground.
Electrical wall outlet having two plug receptacles.
A 120 volt duplex outlet is the main type of outlet for residential outlet system. The wires are typically white and black, and there should only be two of them.
Black, white, and copper.
No. You can split the hot feeds and you can split the neutral feed, but both outlets of a standard duplex receptacle share the ground.
2 Amp
No a 208 volt outlet does not need a neutral. 208 volts is the line voltage between any two legs of a three phase 208 volt system.
Zero, or very close to it. If there is a large neutral current flowing, voltage drop on the neutral leg could cause a volt or so to read between the two. If you read full line voltage, the outlet is wired wrong!
Call an electrician.
it is the pressure difference between inlet and outlet of pump.
There is an open circuit on neutral. You should have power between hot and neutral, as well as between hot and ground. Note well, however, that you should not pull any power between hot and ground, because ground is not intended to be a current carrying conductor - it is only there as a protective earth ground in the case of fault. You can not easily tell, at the outlet, if neutral and ground is reversed - you need to pull a load and then double check with a clamp on ammeter at the distribution panel.