Question
Question: Two wires from electric poles come to our houses. These two wires are called: (A) Dead wire and li...
Two wires from electric poles come to our houses. These two wires are called:
(A) Dead wire and live wire
(B) Live wire and neutral wire
(C) Neutral wire and positive wire
(D) Positive wire and negative wire
Solution
Electricity is generated at power stations. It is brought to the electric poles in our street by two thick copper wires or aluminium wires fixed at tall poles and from electric poles situated in our street, by two insulated wires.
Complete Step by Step Solution: All electricity to your home comes through the service drop. If the service drop goes down, all power in your home will shut off. Catastrophic events, such as downed trees, large fallen limbs, or heavy ice build-up, can take down a service drop. Fallen service drops are extremely dangerous, since they carry enough electricity to power an entire house. Do not approach a fallen service drop.
A standard service drop includes three cables, or conductors. Two are insulated "hot" cables, each carrying 120 volts of electricity. A third cable, usually bare (un-insulated) aluminium, serves as the neutral conductor and provides structural support for the entire service drop.
In simpler words, electric current is brought to our homes from the power stations by two thick copper wires or aluminium wires fixed at tall poles and from electric poles situated in our street, two insulated wires N and L come to our house. These two wires are called neutral wire and live wire.
Hence the correct answer is Option B.
Note: Electrical distribution network is generally divided into two categories:
1. High tension (HT) network
2. Low tension (LT) Network
In a high tension network, electricity transmission is done at higher voltages. These voltages normally range from 400KV to 11KV in India. These generally have three wires, normally called as conductors. Each conductor stands for one phase of voltage. Hence three conductors constitute the RYB phases. The towers we see in the fields or country side or along the highways transmit electricity at 400 or 220 KV. The 33KV or 11KV poles we can see in our street as the big poles other than the domestic supply poles (from which the supply comes to our home).
In low tension (LT) network the electricity is supplied to our homes from the distribution transformers normally mounted on poles in India. The supply from the transformer reaches our home through the wires going across the poles. These wires (bare metallic conductors) may be 3,4 and 5 in count.
3 wire: only one phase and one neutral. Third wire is street light.
4 wire: three phases and one neutral.
5 wire: three phase, one neutral and one for street light.
Nowadays instead of separate wires, a twisted black cable known as AB cable (aerial bunch cable) is used to prevent electricity theft by direct hooking. This cable has four wires twisted into a single cable separated by insulation.