Resistance and ohm's law with light bulb

[trustabdy]

Homework Statement

the tungsten filament of a light bulb has a resistance of .07 ohm. if the filament is 27 cm long, what is the diameter

Homework Equations

R= p(L/A)

Area of a circular cross section = (PiD^2/4)

The Attempt at a Solution

R= p(L/A) A= (pL)/r

Homework Statement

resistance .07 ohm. lengh= .27m, resistivity= 5.6x10^-8
diameter ?

Homework Equations

A= (pL)/r

 

[trustabdy]

can i get some help

 

[marcusl]

Ok, you have the right equations. From the last equation you wrote and the values you listed, what is the area A?

Once you have that, find the diameter from d=2*sqrt(A/pi).