A common flashlight bulb is rated at 0.2A and 2.9V. If the resistance of the bulb's tungsten filament at room temperature (20°C) is 1.10Ω, estimate the temperature of the tungsten filament when the bulb is turned on.
2007-02-11 13:04:54 · 4 answers · asked by brilliantdance12 1 in Science & Mathematics ➔ Physics
I would try this. Calculate rated resistance using E = IR (solve for R). Assume that the increase in resistance for tungsten is linear (in the range of interest). Form a ratio of room temperature resistance / room temperature in degrees Kelvin (use absolute temperature) = rated resistance / unknown temperature x. Convert x to degrees C. Good luck.
2007-02-11 13:43:53 · answer #1 · answered by Kes 7 · 0⤊ 0⤋
At full brightness (a few milliseconds after turning on) the filament temperature will be around 4000 degrees fahrenheit.
2007-02-11 13:32:13 · answer #2 · answered by Mr. Peachy® 7 · 0⤊ 0⤋
Military Grade Tactical Flashlight : http://FlashLight.uzaev.com/?MsWv
2016-07-11 00:19:32 · answer #3 · answered by ? 3 · 0⤊ 0⤋
Tungsten (W) 20C when the bulb is turned on it will take seconds for it to heat up. Praise St Jude.
2007-02-11 13:14:08 · answer #4 · answered by Anonymous · 0⤊ 0⤋