Are light wires live when switch is off?
Normally, hot is switched. Neutral and ground are not switched. Normally, that results in a safe environment where this is nothing “live” when hot is switched off. Fixtures wired correctly so that the wires that should be hot are hot and the wires that should be neutral are neutral.
Do I need to turn off power to change light?
A correctly wired light fixture will be “dead” if the switch is off. I can change the hot wires without actually touching the copper wire, and the neutral and ground wires will not shock you. The official answer is, “Always turn off the breaker before doing electrical work”.
Why fuse is connected with live wire?
The fuse is connected to the live wire so that the appliance will not become charged (have a potential difference of 230 V) after the fuse has melted due to excessive current. Fuses must be fitted onto the live wire so that when it blows, it will disconnect (isolate) the appliance from the high voltage live wire.
Which wire is used for fuse?
Which material is generally used in a fuse wire? Answer: An alloy of lead and tin as it has a low melting point and a very high resistance.
Why a fuse is made of very thin wire?
Because it just acts as a normal electric contact in the circuit or wiring. In order to reduce the area and to maintain a minimum resistance to generate heat, fuses are made as thin. A fuse wire should not have high resistance or low resistance. That is the fuse thickness increases with the current rating.
Why should a fuse have high resistance?
A fuse wire should have a high resistance so that according to (1), a lot of heat is generated and it is easier for the fuse wire to reach its melting point. Also, a high resistance decreases the current flowing in the circuit than what would have been in the absence of it.
How much resistance should a fuse have?
If the reading is between 0 and 5 Ω (Ohms), the fuse is good. A higher reading indicates a bad or degraded fuse. A reading of OL (Over Limit) definitely means a blown fuse. If the fuse is blown, replace the fuse with one that is exactly the same (see panel).