answersLogoWhite

0


Best Answer

Wire 1 has radius R, and wire 2 has radius 2R. Wire 1 has length L and wire 2 has length 2L. Since resistance is inversely proportional to cross sectional area and proportional to length resistance of wire 1 is:

c*L/pi*R^2, where c is a constant based on the material.

The resistance of wire 2 is:

c * 2L/pi *(2R)^2, or squaring the 2R term we have c * 2L/pi * 4R^2, and simplifying we have: c*L/2pi*R^2.

Now, to get the ratio of wire 1 to wire 2 we divide equation 1 by equation 2 and simplify:

c*L/pi*R^2 / c*L/2pi * R^2. When you divide a fraction by another fraction you invert and multiply, so this becomes

c*L *2piR^2 / c*L *pi * R^2. Each of the variables cancel leaving the ratio of resistance of wire 1 to wire 2 is 2:1, or wire 1 has twice the resistance of wire 2 even though wire 2 is twice as long.

An Alternative Answer

Resistance is directly proportional to length, and inversely proportional to cross sectional area. The cross-sectional area of a circle is proportional to the square of the diameter. So, conductor 2 is twice as long, so you can double its resistance; but its diameter is doubled, so its resistance is then reduced by a quarter. So the resistance of conductor 2 is half that of conductor 1!

User Avatar

Wiki User

10y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: Wires 1 and 2 are made of the same metal. Wire 2 has twice the length and twice the diameter of wire 1. What is the ratio of the resistances of the two wires?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Continue Learning about Engineering
Related questions

What length of wire of diameter 1mm can be made from a 1cm cube of metal?

Approximately 127 cm length of a wire with a diameter of 1mm can be used to make a 1cm cube of metal.


Why do spark plug wires have resistance?

All wires have a resistance, as does everything else in the universe. Conductors like metal and carbon generally have low resistances where as non conductors have a very high resistance. Think of it like friction, but electric.


A 1.0 m length of metal wire is connected to a battery and a current of flows through it. What is the diameter of the wire The resistivity of the metal is?

To calculate the diameter of the wire, we would need to know the resistivity of the metal, the current flowing through the wire, and the potential difference across it. Without this information, we cannot determine the diameter solely based on the length of the wire.


What does drawn into a wire means?

"Drawn into a wire" refers to the process of stretching and pulling a material, such as metal or plastic, through a series of dies to reduce its diameter and increase its length. This process is commonly used to produce wires with specific diameters for various applications.


Can a metal be stretched into a wire?

Yes, most metals can be stretched into wires through a process called drawing. This involves pulling the metal through a series of decreasingly smaller dies to reduce its diameter while increasing its length. The resulting wire retains the properties of the original metal.


What are thin wires made out of?

metal if its not metal than its not a wire


Is wire metal non metal?

The wires themselves are usually made of a metal such as copper.


Is wire metal or non metal?

The wires themselves are usually made of a metal such as copper.


What is thew cost of a metal pipe with the diameter of 3 inches?

That's going to depend on: -- the thickness of the pipe's walls -- the length of the piece you want to buy -- the material of which the pipe is composed -- where you buy it


A US cent coin has a diameter of 1.9000cm 20.00C.The coin is made of metal alloy for which the coefficient of linear expansion is 2.610k.What would its diameter be a.on a hot day in Death Valley 48.0?

To find the new diameter of the coin in Death Valley at 48.0°C, you can use the formula for linear expansion: Lf = Li * (1 + α * ΔT), where Lf is the final length/diameter, Li is the initial length/diameter, α is the coefficient of linear expansion, and ΔT is the change in temperature. Plugging in the values, Lf = 1.9 cm * (1 + 2.61e-5 * 48). Calculate to find the new diameter.


What is copper metal used for?

Pipes, wires.


What kind of metal is used in wires?

copperr