Is Negative the live wire?
The "live" wire will have positive and negative voltages (periodically) with respect to the neutral (and therefore with respect to ground as well).
For DC power, the red wire is positive and the black wire is negative. For AC power, the black wire is the phase 1 hot wire, which means it's positive.
In general, red wires are used to indicate positive voltage, while black wires are used to indicate negative voltage.
A live wire is actually positive wire, And Neutral wire is the negative wire. Current flows from positive terminal house and then negative terminal. So, to prevent the devices from electrical damages, fuse is connected before them. That is to live wire.
The live wire of domestic circuits is usually red and is at high voltage. The neutral wire is black and has voltage close to that of the ground. The potential difference between these two wires in India is about 220 V. The earth or ground wire provides safety against faults and current leaks.
The black wire is the "hot" wire, it carries the electricity from the breaker panel into the switch or light source. The white wire is the "neutral" wire, it takes any unused electricity and current and sends it back to the breaker panel.
The protective ground is green or green with yellow stripe. The neutral is white, the hot (live or active) single phase wires are black , and red in the case of a second active.
Complete step by step answer: Red color code is used for live wires whereas green for ground and black for neutral.
The positive wire, also commonly called the hot wire, will typically be black in color. It is the source of the electricity. The electrical current travels from the outlet or other power source on the positive wire, so if it is plugged in anywhere, it should be considered a live (and dangerous) wire.
Switching which wire is connected to positive or negative (without regard to color) will typically RUIN/TOAST/BLOW UP most anything electronic. Of course incandescent lamps don't care, and DC motors will typically run in the opposite direction if you switch the polarity.
Which cable wire is positive?
Find the batteries and their terminals. Each battery has two metal terminals. One is marked positive (+), the other negative (-). There are also positive and negative cables in the jumper cable set.
One of the easiest ways to know if a wire is live is to use a voltage checker or a current checker. These are simple devices that you can touch to any wire, and it will tell you if there is electricity running through it.
Black: Hot Wire
The wire that carried the electricity was the hot or live wire. In your household's wiring, this wire is typically black, but it may also be red (more on that in a second). Black wires are always hot wires that carry electricity.
Use a test lamp. It's just a light bulb with two wires coming out of the holder. Touch one lamp wire to one of the black wires and the other lamp wire to the ground wire. If the bulb lights up, the wire is hot.
There would be a shock hazard, and some devices might not work correctly. Depending on where exactly the wires are flipped, ground fault detecting circuit breakers may become ineffective. All around, this is a bad idea. Save this answer.
If for some reason the live and neutral conductor wires are reversed then a 'reverse polarity' condition is produced.
As you can see, the neutral wire is essential to your home's electrical system. Without it, there would be no circuit for electricity to flow along and complete its circle back to the power source.
In metal wires, current is carried by negatively charged electrons, so the positive current arrow points in the opposite direction the electrons move. This has been the sign convention for 270 years, ever since Ben Franklin named electric charges with + and - signs.
One of the easiest ways to know if a wire is live is to use a voltage checker or a current checker. These are simple devices that you can touch to any wire, and it will tell you if there is electricity running through it.