What is the Optimal Diameter for a 12.0 Ω Nichrome Wire at 20°C?

AI Thread Summary
To achieve a resistance of 12.0 Ω with 46 m of nichrome wire at 20°C, the optimal diameter calculated is approximately 2.3 mm. The resistance formula used is R = ρ(L/A), where ρ for nichrome is 108e-8. The area (A) was determined first, leading to the diameter calculation using A = (1/4)π(d²). The discussion emphasizes the importance of unit consistency throughout the calculations. The final diameter ensures the wire meets the specified resistance requirement.
phy112
Messages
37
Reaction score
0

Homework Statement



If 46 m of nichrome wire is to have a resistance of 12.0 Ω at 20°C, what diameter wire should be used?

Homework Equations



R=\rho(L/A)

The Attempt at a Solution



I tried and I got 2.1. The \rho of nichrome is 108e-8
 
Physics news on Phys.org
First solve for the variable you are looking for and put it on one side. Keep your knowns on the other side. Remember that A stands for area, and area is related to wire diameter.

I am online for a bit, so give it a go. DON'T FORGET YOU UNITS!
 
ok yeah i got 2.3 mm. after i figured out A. I figured out diameter doing A=1/4pi(dsquared)
 
ok i got it right. thanks!
 
Good for you!
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

Electric current and resistance question
Replies
2
Views
2K
Calculate number of turns for an electric heater
Replies
3
Views
2K
Current and resistance of wire heating up water
Replies
4
Views
4K
What is the density of pure chromium in g cm^-3?
Replies
44
Views
4K
Length and Area of Cylindrical Nichrome Resistor
Replies
3
Views
2K
Lab: Plot graph of resistance, R (in Ohms) versus 1/d^2
Replies
21
Views
11K
Current through two different types of wire of different diameter
Replies
5
Views
13K
Heat Transfer by Nichrome wire and Steel
Replies
20
Views
6K
Electric field in a wire with same current as another wire
Replies
1
Views
2K
Nichrome and Copper Circuit w/ Electron Mobility
Replies
31
Views
8K

Hot Threads

Recent Insights

Back
Top