a. .50 ohms
b 2 ohms
c. 120 ohms
d 240 ohms
2007-03-30 09:34:20 · 5 answers · asked by mysterious_qt 2 in Science & Mathematics ➔ Physics
depends on the voltage I go for 0.5 ohms if you have 240 volts, and for 2 ohms if you have 120 volts
2007-03-30 09:37:33 · answer #1 · answered by gjmb1960 7 · 0⤊ 0⤋
Household circuits in the USA run at 120 volts. When the bulb is lit, it consumes 60 watts, and under those conditions the equivalent resisance is e squared divided by watts or 120x120/60 = 240 ohms.
bulb filament resistance increases with temperature. it you were to measure it at room temperature with an ohm-meter you would get only about 24 ohms.
sometimes a bulb is used in an electrical circuit to take advantage of this resistance swing which helps it to regulate current drawn through the circuit. in the 1930s these were known as ballast tubes.
2007-03-30 17:21:34 · answer #2 · answered by lare 7 · 0⤊ 0⤋
R = V^2/P
Assuming nominal voltage of 120 V,
R = (120^2)/60 = 240
2007-03-30 16:54:15 · answer #3 · answered by Helmut 7 · 0⤊ 0⤋
Errr.Depends on the voltage supply
P= (V^2)/R
In US, V is 120V Rest of the world, its 220 or 230V
2007-03-30 16:39:06 · answer #4 · answered by shrek 5 · 0⤊ 0⤋
D. its ohms law, i got a link here you can use if you like:http://www.angelfire.com/pa/baconbacon/page2.html
2007-03-30 16:38:06 · answer #5 · answered by hodgetts21 5 · 0⤊ 0⤋