Assignment 1 - Laptop Charger

Let's take a look at the charger for my Lenovo Y580. The specs are listed on the charger itself:

The ADP-120LH B charger

From here we can see it outputs 19.5 V at 6.15 A. Ohm's Law, V=IR, gives us approximately 3.17 ohms of resistance.

Multiplying voltage and current, we get 199.93 W of power, or .19993 kW.

BGE tells us the maximum I'll pay for an hour of electricity at this time of year is 11.924 cents per kWh. Multiplying power by price shows that I'm paying a maximum of 2.384 cents for every hour my laptop is plugged in.