Question

A rod of 2m length and a square (2.0mn times 2.0 mm) cross section is made of material with a resistivity of 6 times 10^-4 rm. If a potential difference of 0.50 V is placed across the ends of the rod, at what rate is heat generated on the rod?

Answer 1

resistance of rod will be given as :

R = rho L / A

R = (6 x 10^-4 ohm m ) (2 m) / (2 x 10^-3 x 2 x 10^-3 m^2)

R = 300 ohm

P = V^2 / R = 0.50^2 / 300

P = 8.33 x 10^-4 W Or 0.833 mW