Time remaining:
physics electric and current circuit

label Physics
account_circle Unassigned
schedule 0 Hours
account_balance_wallet $5

A carbon rod with a radius of 1.4 mm is used 

to make a resistor. 
What length of the carbon rod should be 
used to make a 1.3 Ω resistor? The resistivity 
of this material is 3.9 × 10−5 Ω · m . 
Answer in units of mm.
Apr 11th, 2015

R = ρL/A 

ρ is resistivity of the material in Ω-m 

L is length in meters 

A is cross-sectional area in m² 

A = πr² = π(0.0014)² = 4.39e-3 m² 

1.3 = (3.9e-5) L / (4.39e-3) 

L = [ 1.3 * (4.39e-3) ] / (3.9e-5)

L = 146.33 mm or 0.14633 m

Apr 11th, 2015

Did you know? You can earn $20 for every friend you invite to Studypool!
Click here to
Refer a Friend
Apr 11th, 2015
Apr 11th, 2015
Sep 23rd, 2017
Mark as Final Answer
Unmark as Final Answer
Final Answer

Secure Information

Content will be erased after question is completed.

Final Answer