Converting the diameter for the equation l = RA/rho

  • Thread starter Thread starter vikz
  • Start date Start date
  • Tags Tags
    Diameter
AI Thread Summary
To determine the length of an aluminum wire needed to create a 20 Ohm coil, the diameter must first be converted from 0.5 mm to meters, resulting in 0.0005 m. The formula l = RA/rho is used, where R is resistance, A is the cross-sectional area, and rho is resistivity. The cross-sectional area A can be calculated using the diameter, with A = π(d/2)². The resistivity of aluminum is given as 2.8 x 10^-6 Ohm cm, which should be converted to Ohm m for consistency in units. Understanding these conversions and calculations is essential for solving the problem accurately.
vikz
Messages
3
Reaction score
0

Homework Statement



An aluminium wire has diameter 0.5 mm and resistivity 2.8 X 10-6 Ohm cm. How much lenth of this wire is required to make a 20 Ohm coil?

Please tell me how to convert Diameter 0.5mm? what's the procedure?
After that I can directly apply-
l = RA/rho
 
Physics news on Phys.org
vikz said:

Homework Statement



An aluminium wire has diameter 0.5 mm and resistivity 2.8 X 10-6 Ohm cm. How much lenth of this wire is required to make a 20 Ohm coil?

Please tell me how to convert Diameter 0.5mm? what's the procedure?
After that I can directly apply-
l = RA/rho


What do each of your variables signify, R, A, rho?
 
sjb-2812 said:
What do each of your variables signify, R, A, rho?

R = Resistance
rho= Electrical Resistivity of the material of the conductor.
A = Area of cross-section

SI unit of resistivity is Ohm m
 
Last edited:
vikz said:
R = Resistance
rho= Electrical Resistivity of the material of the conductor.
A = Area of cross-section

Which of those variables depends directly the radius (or diameter) of the wire?
 
gneill said:
Which of those variables depends directly the radius (or diameter) of the wire?

R is inversely propositional to 1/A
 
Last edited:
Suppose that d=0.5mm is the diameter of the wire. What is the cross sectional area, A?
 

Thread 'Errors and significant figures'

I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
View full post »
Thread 'A cylinder connected to a hanging mass'

Thread 'A cylinder connected to a hanging mass'

Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
View full post »

Similar threads

Long distance electrical transmission efficiency
Replies
2
Views
2K
Lab: Plot graph of resistance, R (in Ohms) versus 1/d^2
Replies
21
Views
11K
Calculting the length of a solenoid
Replies
7
Views
10K
Measuring a Coil of Wire With Ohmmeter and Balance
Replies
3
Views
2K
Platinum resistance thermometer and Kirchoff's Laws
Replies
1
Views
3K
Calculating Copper Wire Gauge for Resistance Thermometer Bridge Circuit
Replies
6
Views
2K
Question for the resistance of the wire
Replies
4
Views
4K
Voltage difference, current flow
Replies
5
Views
9K
Current through two different types of wire of different diameter
Replies
5
Views
13K
Resistance in a wire, sanity check about units.
Replies
3
Views
2K

Hot Threads

Recent Insights

Back
Top