How Does Current Flow Affect Entropy in a Resistor and the Universe?

[Brewer]

Homework Statement

A 50 ohm resistor carries a current of 250 mA and is maintained at a constant temperature of 303K by thermal contact with a heat sink.

Calculate the entopy change of

i) the resistor, and
ii) the universe,

if the current flows for 30 seconds.

Homework Equations

dS >= 0?

The Attempt at a Solution

I'm not sure how to attempt this question for a physical problem. Up until now I've been restricted to doing questions of this type based upon ideal gases, so I'm not sure how I would apply that to a physical system like this. Any hints anyone?

 

[Brewer]

Right, I've had another look at this.

I've said that dQ=dW and that work = power * time, so dW = Pdt = I*I*R*dt

From here I've substituted this into the equation $$dS = \int \frac{I^2R}{T}dt$$ with limits 0 and 3.

Following this through I get an answer of 0.031 J/kg. Does this sound about right? Then for the entropy change of the universe it'll be just the negative of this answer?