What Happens When a Wire Is Stretched To Double Its Length?

What Happens When a Wire Is Stretched To Double Its Length? | howtoimprovehome.com

Wires have many properties, such as resistance and resistivity. Stretching or reducing the wire’s length can lead to different consequences. It’s important to understand these results to use the wire efficiently. So, What Happens When a Wire Is Stretched To Double Its Length?

If a Wire Is Stretched To Double Its Length, What Happens to Its Resistivity?

Its resistivity will not change because resistivity is a physical property. Physical properties are specific to the material of the conductor. This means that If the wire is made out of copper, which has 1.72 x 10-8 Ωm resistivity. The resistivity will stay the same whether the length is stretched or reduced.

Each matter has its physical properties, which can’t be affected unless there is a physical change. Physical properties have many other examples:

  • Color
  • Density
  • Hardness
  • Melting Point
  • Boiling Point

If a Wire Is Stretched To Double Its Length, What Happens to Its Resistance?

Its resistance increases fourfold because the wire’s volume stays the same even if its length is stretched. When the length of the wire is stretched to double, the area decreases by half since the resistance can be calculated using this equation R= ρ*L/A, where ρ refers to the wire’s resistivity, L refers to the wire length. A refers to the wire’s area.

Since the wire’s resistivity is a physical property, it’s constant. Now, the wire has a length equal to double its previous length Lnew = 2Lold. In addition, its area decreased by half Anew=Aold/2. So, the new resistance equals R= 2L/A/2= 4R.

Another way to calculate the resistance is by using Ohm’s law R= V/I. However, increasing the current doesn’t mean the resistance will change. You can think of it as a road; increasing the number of cars passing through the road doesn’t decrease the obstacles or pumps on the road. Only the length and the area of the wire affect the resistance.

If a Wire Is Stretched To Double Its Length, What Will Be the Strain?

The strain will be 1 because if the length is 2 using the equation longitudinal strain = change in length / original length. The strain equals 4-2/2= 1; therefore, the strain will always be 1 as long as the wire stretches to double its length.

When a Wire Is Stretched To Double Its Length, Is Its Radius Halved?

No, its radius is reduced to a quarter of its value. The volume of the wire always stays the same, even if the wire is stretched to double its length. When the length stretches, the area is reduced, so the volume stays constant. Since the wire’s area depends on the radius A = π r², the radius also is reduced. But the radius is not halved; it is reduced to a quarter of its value.

Because the radius in the area formula is squared or raised to power two if the area decreases by “2,” the radius decreases by “22.

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What Will Be the Resistivity of a Wire if It Is Stretched To Double Its Original Length Without Loss of Mass?

The resistivity will stay the same because it’s a physical property. Resistivity can be calculated through this equation R= ρ*L/A, where ρ refers to the wire’s resistivity, L refers to the wire length, and A refers to the wire’s area. And It’s independent of the external dimensions or the volume of the wire. So, if the length is stretched or reduced, the resistivity stays the same.

For example, copper has 1.72 x 10-8 Ωm resistivity, and if a wire is made of copper, its length is stretched from 2 cm to 4cm. Then we calculated its resistivity using R= ρ*L/A, and the resistivity equals 1.72 x 10-8 Ωm. Because the volume stays the same, and this happens by the area being reduced to half its value.

When a Wire Is Stretched to Thrice Its Original Length, Does the Volume Remain the Same? Why?

Yes, the volume will remain the same because the length is stretched to thrice its original length. And the cross-sectional area will be reduced to a third of its value. It’s a matter of relativity; when the wire’s length increases, its area is reduced if the length is stretched to double its original value.

The area will be reduced to half of its original value. Contrary to what appears in the equation or the formula of resistance R= ρ*L/A, the resistance is only affected by the length and the area of the wire. Because the resistivity “ρ” is a physical property of the material from which the wire is made, and from this equation, we can conclude that length is inversely proportional to the area.

What Are the Physical Properties of the Wire Matter?

Wires can be made of different materials; each material or matter has different physical properties that can affect it. Any matter or material consists of very small particles called atoms. Atoms are the particles that take up space, responsible for volume and mass properties. Thes properties are specific and differ from one matter to another.

The physical properties are different from the chemical properties and are independent of each other. Physical properties have many other examples:

  • Hardness
  • Density
  • Color
  • Boiling Point
  • Melting Point

To know which is a physical property and which is not, it’s a physical property if you can measure it.

What Are The Types of Properties of Matter?

The matter has two types of properties, and if the property is dependent on the amount of matter, it’s called extensive property. But if the independent of the matter’s amount, it’s called intensive property. Extensive properties, for example, are volume and mass. Meanwhile, an example of an intensive property is color and density.

Extensive Properties of Matter

To call a property of matter an extensive property, it must depend on the amount of matter. For example, mass and volume are dependent on the amount because the mass of matter or the volume increases as the amount of the matter increases.

Intensive Properties of Matter 

An intensive property must be independent of the amount of matter; for example, color is an intensive property. Because no matter the amount of a matter, the color stays the same. Another example of intensive properties is density. 1 gram or 1 ton of nails will still sink in the water. Because its density is larger than water, density stays the same no matter the amount of the matter.

Why Do We Need To Understand Physical Properties?

Any matter has physical properties, so we need to understand them to understand the matter itself. The matter can have 3 different shapes or phases gas, liquid, and solid. Depending on its physical properties, it takes a different shape.

What Are the Chemical Properties of the Wire Matter?

Chemical properties are different from physical properties, and they can be distinguished or measured only when the matter reacts or transforms into other types of matter. There are many different examples of chemical properties, flammability, reactivity, and the matter’s ability to rust. Reactivity can be defined as the ability of matter to react with other materials. Other examples of chemical properties are:

  • Acidity
    If a substance can react with an acid, it’s called acidity, and it’s a chemical property. An example of acidity is when a material reacts with acids and forms compounds. 
  • Flammability
    Some materials can react with oxygen and burn, resulting in other compounds such as carbon dioxide. This ability is called flammability; an example of a material with flammability property is paper.
  • Toxicity
    Substances can be harmful sometimes and have the ability to toxin an organism. This happens when the substance reacts with the organism’s body.

Conclusion

To sum up, resistance depends on the wire’s length and area. If one of them changes, the resistance changes. But the resistance is directly proportional to the length. Meanwhile, it’s inversely proportional to the wire’s area. However, resistivity isn’t the same as resistance. And it’s independent of the wire’s volume or dimensions. 

The resistivity depends on the type of matter because it’s a physical property. To clarify more, it’s an extensive physical property, which means that it doesn’t change with an increase in the matter amount. Understanding the physical properties of matter is important to understanding the matter itself.

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