wire
Definition
A wire is a long, thin, solid piece of metal that is used to conduct electricity or heat. Wires are typically made of copper, aluminium, or steel. The metal is drawn into a long, thin strand, and then it is coated with a protective layer, such as insulation.
Wires are used in many different applications, including:
- Electrical wiring: Wires are used to carry electricity from power sources to appliances and devices.
- Heat conduction: Wires can be used to conduct heat, such as in heating elements and toasters.
- Structural support: Wires can be used to provide structural support, such as in bridges and buildings.
- Manufacturing: Wires are used in the manufacturing of many different products, such as cars and aeroplanes.
The type of wire that is used depends on the specific application. For example, electrical wiring typically uses copper wire because it is a good conductor of electricity. Heat conduction applications often use stainless steel wire because it is resistant to corrosion. Structural support applications may use high-strength steel wire.
How can the word be used?
The electrician wired the house.
Different forms of the word
Noun:
- a long, thin piece of metal that is drawn out into a thread.
- a communication system that uses wires to transmit signals.
- a device that is used to transmit electrical current.
Verb:
- to fasten something with wire.
- to make something out of wire.
Etymology
The word "wire" comes from the Old English word "wīr", which also means "a long, thin piece of metal".
The first recorded use of the word "wire" in English was in the 9th century.
Question
Why is wire used in electrical appliances?
AQA Science Exam Question and Answer
Question:
Discuss the concept of electrical resistance in wires and its relationship to wire thickness and material. Explain how factors like length, cross-sectional area, and material influence the resistance of a wire in an electrical circuit.
Answer:
Electrical resistance refers to the opposition that a material offers to the flow of electric current. In wires, resistance is influenced by several factors, including the thickness of the wire (cross-sectional area) and the material it is made of.
The relationship between wire thickness and resistance is inversely proportional. Thicker wires have a larger cross-sectional area, allowing more space for current flow and reducing resistance. Thinner wires, on the other hand, offer less space for current and have higher resistance.
Wire length also affects resistance. Longer wires present more obstacles to the flow of electrons, resulting in increased resistance. In contrast, shorter wires have fewer obstacles and therefore lower resistance.
The material of the wire plays a significant role. Some materials, like copper, have lower resistance and are commonly used in conducting electricity. Others, like nichrome, have higher resistance and are used in applications where heat generation is desired, such as in heating elements.
The relationship between resistance (R), length (L), cross-sectional area (A), and resistivity (ρ) is given by the formula R = ρ * (L / A). This equation underscores the importance of both wire length and material in determining resistance.