A ground (earth) wire is needed in not just a light circuit but in all circuits that are now installed.
batteries, wire, connectors, and light bulbs
By earth wire I am assuming you mean the bare wire and that a black and white wire are connected to the light. If when you connect the earth wire and breaker trips then there is a short between black and earth. It could be a bad ground connection, an internal short in the light fixture where black wire "hot" is connected to metal on the fixture through a nick in wire.
No, pencil lead (graphite) cannot conduct electricity like a metal wire can. In order to light a light bulb, a material that can conduct electricity, such as a metal wire, is needed to create a closed circuit.
The purpose of a common wire in a light switch circuit is to provide a return path for the electrical current to complete the circuit and allow the light to turn on or off.
The purpose of the common wire in a light switch circuit is to provide a return path for the electrical current to complete the circuit and allow the light to turn on or off when the switch is toggled.
Earth wire is meant to protect the user in case there is earth fault in the device or circuit. Only earth wire alone is not sufficient. It needs to be provided with suitable circuit breaker that breaks the circuit automatically.
If it is a 110 volt light it can safely run on a 20 amp circuit with AWG # 12 wire.
Electricity flows through a wire connected to the light bulb, providing the energy needed to illuminate it. When the circuit is completed, electrons move through the wire and generate light and heat in the bulb through the process of electrical resistance.
For a 60 amp electrical circuit, the appropriate size of copper wire needed is typically 6 gauge.
In the visible spectrum or the infrared? Either way, if your earth wire is glowing you have a problem. Your earth wire is not intended as a current carrying wire. If the wire is loaded to the point that it glows then your circuit/breaker is not wired correctly and the earth wire is being used as an unintended path and is a hazard. Earth wires are not sized properly to carry current.
Yes, a loose neutral wire can effect the operation of Earth Leakage Circuit Breaker.
The black wire is not really needed in a circuit because it has a negative voltage