1. A cylindrical resistor with radius K and length L is made from a material with conductivity σ. The potential difference between the circular ends is V.

a. What is the current that flows from one end to the other?

b. What is the resistance?

c. Show that the resistance you found is = (see attached) where ρ is the resistivity of the

material, and A is the cross-sectional area of the cylinder.

(Hint: The electric field is constant throughout the resistor, but its value is not given.)

2. A thick disk has a hole in it. The disk is constructed such that the inner rim and outer rim are metal and held at a potential difference V. Between the two metal rims is a material with conductivity σ. The radius of the inner rim is R1, and the radius of the outer rim is R2. The disk has a height of H.

a. What is the current that flows from the inner rim to the outer rim?

b. What is the resistance?

(Hint: A thick disk is basically a short cylinder.)