1. Resistors Intro to ECSE Analysis K. A. Connor Mobile Studio Project
Center for Mobile Hands-On STEM
SMART LIGHTING Engineering Research Center
ECSE Department
Rensselaer Polytechnic Institute
Intro to ECSE Analysis

2. What is a Resistor? Converts electrical energy to heat.
Obeys Ohm’s Law

3. Examples Incandescent lightbulb Toaster Hair Dryer
Electric Space Heater
Hair Curler
Electric Stove Burner
Heating Element in an Oven
Photocell
Electric Motor Coil
Damp Soil, Wood, etc.
Salt Water
Electrical Components
Human Body
Fuse
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4. Conductor
How Does Copper Behave?
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5. Copper Resistivity is 1.7x10-8 Ω/m
Length is 1m, Diameter is 2mm (12 AWG)
R = 5.4mΩ
I = 20A (usual limit for household circuit)
Electron density n = 8.46 x 1028 m-3
J (current density) = Current/Area = 2.5x107 A/m2
J = nevd & e = 1.6 x Coulombs
vd ≈ 2mm/s
Snails and slugs travel at speeds that vary from slow (0.013 m/s) to very slow ( m/s).
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6. How Fast is That? vd ≈ 2mm/s About 7 meters per hour
For the very small currents we will typically use (1 – 20mA), speeds are even smaller!
Prov. If you work slowly but constantly, you will succeed better than if you work fast for a short while and do not continue. (Associated with Aesop's fable of "The Tortoise and the Hare.") It also helps if there are 1029 of you per cubic meter working together.
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