Finding Length and Area of Tungsten Wire Resistor

do you think that this is as level or a2 level

  • Total voters
    1
nomnom
Messages
1
Reaction score
0

Homework Statement


the actual question is
the resitivity of tungsten metal is 4.9x10to the power of -6 Ωcm. choose appropriate values for length and cross-sectional area for a home made wire resistor of resitstance 20Ω

Homework Equations



r=pl/a
r-resistance
a-cross sectional area in m squared
l- length of wire in meters
p is resistivity of the material in ohm(meters)

The Attempt at a Solution


i don't even know wher to start all i know is that i need to find L and A but i only know p's value, please help,

 
Physics news on Phys.org


Hello, and welcome to PF. I can't answer the poll because I don't know what it is asking. I don't, for future reference, think this problem belongs in "advanced physics."

The reason you can't "solve" this problem is because you are supposed to come up with the values yourself. You could look up the standard gauges of wire (most people use 16-26awg at the very most/least) to get a range of possible area, and from there solve for length..
 

Thread 'Initial conditions for orbits around a wormhole'

Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
View full post »

Thread 'Help to convert units of a simple formula'

The value of H equals ## 10^{3}## in natural units, According to : https://en.wikipedia.org/wiki/Natural_units, ## t \sim 10^{-21} sec = 10^{21} Hz ##, and since ## \text{GeV} \sim 10^{24} \text{Hz } ##, ## GeV \sim 10^{24} \times 10^{-21} = 10^3 ## in natural units. So is this conversion correct? Also in the above formula, can I convert H to that natural units , since it’s a constant, while keeping k in Hz ?
View full post »

Similar threads

Heat flux through a material with variable heat conductance
Replies
2
Views
2K
Finding the power loss in a wire of varying cross-sectional area
Replies
8
Views
2K
Calculating Copper Wire Gauge for Resistance Thermometer Bridge Circuit
Replies
6
Views
2K
What Is the Diameter of a Tungsten Filament with a Given Length and Resistance?
Replies
3
Views
18K
Electric current and resistance question
Replies
2
Views
2K
Finding the voltage drop along a tapered wire
Replies
30
Views
2K
Junction Potential: Nichrome Wires of Different Lengths & Areas
Replies
1
Views
3K
Resistance in complex geometries
Replies
6
Views
2K
Length and Area of Cylindrical Nichrome Resistor
Replies
3
Views
2K
How to find the radius of copper wire given resistivity values
Replies
1
Views
23K

Hot Threads

Recent Insights

Back
Top