Quote:
Originally Posted by jamesqf
Oh, and another question for thought: how come the wires in your toaster or electric heater - or indeed, the tungsten filament in an incandescent light bulb - are made of metal, which has a low resistance? Just for the heck of it, I dug out a few old incandescent bulbs, and measured their resistance: 40 W = 30 ohms, 60 W = 17 ohms, 75 W = 13 ohms. Not high resistance at all (though of course it increases with temperature), yet lots of heat.
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Exactly. The wire wound resistors in my car are 1.3, .62 and .33 ohms each. Not mega-ohms or kilo-ohms, just ohms. Very low resistance, generate heat. That is why they are typically located in the duct to aid in cooling. Low setting routes through all three resistors, med low through the .62 and .33 only, med high through the .33 only, and high straight to the blower motor.