[Show all top banners]

rockey07
Replies to this thread:

More by rockey07
What people are reading
Subscribers
Subscribers
[Total Subscribers 1]

rockey07
:: Subscribe
Back to: Kurakani General Refresh page to view new replies
 *******Physics Help***********
[VIEWED 1649 TIMES]
SAVE! for ease of future access.
Posted on 04-11-09 3:38 AM     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

I just came across one physics problem. It looks like a simple problem but i'm not getting any where near to the convising answer. The question goes as follow;


At what temperature will tungsten have a resistivity 5 times that of copper. Assume that the copper is at 20 degree centigrate.


Please somebody help me on this.


 
Posted on 04-11-09 5:55 AM     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

There must be more information. Is there a table of reference where you can look up resistivities and such?

There's this formula for resistance but you also need alpha (temperature coefficient of resistance) for the metal:
R = Ro [ 1 + alpha (T - To)]

Ro = Resistance of Tungsten at 20 C
Given same dimensions, R of Tungsten = 5*R of Copper at 20 C
To = 20 C
alpha = temperature coefficient of resistance of Tungsten
T =?

This is my initial thought though, given you have these values which should be in the back of most physics textbooks. I might have missed something crucial here though, I'm not sure.
Last edited: 11-Apr-09 05:55 AM

 
Posted on 04-11-09 10:30 AM     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

Thanks a lot "bored" you made my day. Finally its making some sens now. Thanks again :-)
 
Posted on 04-11-09 10:45 AM     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

Rockey bhai, get your question right first. Resistivity of a material is a constant. Resistance depends on the temperature and physical attributes of the material.
 
Posted on 04-11-09 11:31 PM     Reply [Subscribe]
Login in to Rate this Post:     0       ?    
 

pret_atma, resistivity might be a constant, but it is only constant under certain conditions. Resistivity of a material can change with temperature, dictated in part by the material's temperature coefficient. So I don't see why you think Rockey's question is invalid.

 


Please Log in! to be able to reply! If you don't have a login, please register here.

YOU CAN ALSO



IN ORDER TO POST!




Within last 7 days
Recommended Popular Threads Controvertial Threads
सालीको चाक
Abortion should be illegal in US
के नेपाल टाट पल्टी सकेको हो ?
Tennessee passed no purchasing online Plan B
Immigration court
USA Master in Nursing
Could crypto be a scam?
How to get quicker Visa application date for B1/B2 Tourism visa from Nepal?
NOTE: The opinions here represent the opinions of the individual posters, and not of Sajha.com. It is not possible for sajha.com to monitor all the postings, since sajha.com merely seeks to provide a cyber location for discussing ideas and concerns related to Nepal and the Nepalis. Please send an email to admin@sajha.com using a valid email address if you want any posting to be considered for deletion. Your request will be handled on a one to one basis. Sajha.com is a service please don't abuse it. - Thanks.

Sajha.com Privacy Policy

Like us in Facebook!

↑ Back to Top
free counters