Entropy Change Q: 10 Ohm Resistor @ 300K, 5A for 2 Mins

[bon]

Homework Statement

A 10 Ohm resistor is held at a temp of 300K. A current of 5A is passed through the resistor for 2 mins. Ignoring changes in the source of current, what is the change of entropy in:
(a) the resistor
(b) the universe

Homework Equations

The Attempt at a Solution

Ok so not sure how to do this..

Obviously i know how to work out the total power dissipated (I^2 R)..

dS = dQ rev/T

now not sure what to do... the process isn't reversible right?


im guessing the total entropy of the universe increases..?

help please! :)

 

[Andrew Mason]

Homework Statement

A 10 Ohm resistor is held at a temp of 300K. A current of 5A is passed through the resistor for 2 mins. Ignoring changes in the source of current, what is the change of entropy in:
(a) the resistor
(b) the universe

What is the temperature of the surroundings?

The overall process is not reversible. But entropy is calculated for the resistor and surroundings separately. Determine the reversible path between the initial and final state for the resistor and calculate the change in entropy for the resistor. Then find the change in entropy for the reversible path between the initial and final states for the surroundings. You will need the temperature of the surroundings though.

AM