Which is brighter, one 120 watt light bulb or two 60 watt light bulbs?
921578
120W would be brighter, and here is why:\n120W light bulb would have higher temperature (rough argument: dQ/dt= c*m-sigma*T^4, at equalibrium c*m = sigma*T^4 =P =V*I, where c= heat capacity per mass), and by Planck's law of black-body radiation will emitt more visible light than Infra Red light, so it's more efficient in producing visble light for the same energy than 2x 60W light bulbs. Great question.
294284
multiply 70x60 to find out
816552
Turn on one light bulb and leave it on for a while. Turn it off\nTurn on a second light bulb and leave it on. Go up stairs.\nThe second switch obviously turns on the bulb that is on.\nThe first switch (you turned on then off) is for the lightbulb that is NOT ON but is warm from being used. \nThe  3rd switch obviously is the one for the unlit lightbulb that's cold.
767776
The Power, P = VI, hence\n\nThe current at 120V is I = P/V = 65000/120 = 541.667 A\nThe current at 1200V is = 54.1667 A\n\nHowever, here the power is carried by TWO parallel lines, each with 0.1 ohms of resistance. That means the effective resistance is given by:\n\n1/Reff = (1/R1) + (1/R2) = 20 or Reff = 0.05 ohms\n\nTherefore, the Power Loss at 120V is\n\nP = I^2R = (541.667)^2(0.05) = 14670.15 watts\n\nThe Power Loss at 1200V is = 146.7 watts\n\nHence the power saving by stepping up to 1200V is\n\n= 14670.15 - 146.7 = 14523.45 watts
233283
a regular light bulb \nas apposed to a floresent
137865
Deppends on the bulb, and it's efficiency, total energy in = total out. 50W at 10 min is 30000 Jouls of energy.\nThe efficency of an average incad. bulb is about 15% efficient, so I would say you get about 4500J of light, and the rest would mostly be heat, about 25500J of heat.\n\nI am not sure how to convert the Jouls into Lumens, and Calories/BTUs, but it can be done.
481822
1.80 or 120\n2.bcuz u need 1 to hold the lightbulb, and 99 the rotate the house. lol im a blonde! =-)\n3.One says "cockadoodledoo" and the other says "any cock'll do"
783681
Fluorescent light is better for seeing the true color of things, but incadescent bulbs are better for the eyes.  While the white light is good for appllications where color clarity is key, the flisker of the bulbs is more straining.  Fluorescent bulbs are also more energy efficient and have a longer lifetime.  The only drawback is that they contain some mercury, so you have to be aware of the regulations regarding the disposal of fluorescent bulbs/tubes.
301420
3 One to screw in the bulb and 2 to keep the beat
1043980
You can, but there is a danger of overheating and fire. Here's why.\n\nThe power of a light bulb in watts is determined by the equation P=V^2/R where V = voltage and R = resistance. The higher power (higher wattage) light bulbs actually have lower resistance, so they draw more current.\n\nThat same current must pass through the wires, socket, etc. These also have resistance. The greater the current that passes through the wire, socket, etc. generates heat from the equation P = I^2 * R.  So, if the current is doubled, there is 4 times as much heat that is generated by the wires, socket, etc.\n\nSockets and wires have different ratings depending on their ability to handle high current and heat. You may have seen ceramic light sockets - they provide better heat resistance that lightweight sockets with plastic that can melt.
1079575
By Ohm's Law, current = voltage / resistance\n\nTherefore the current is 120 / 2 = 60 amps (answer b)
94366
Check your local Home Depot.  40 watt is the 4' bulb with the plant/aquarium label.  (appx $7).  get an inexpensive 4' single bulb fixture with cord and pull chain on/off (appx $8).  If you want rapid start, i believe you're just wanting something that doesn't take a long time to come on.  Just ask if is has a magnetic ballast or a rapid start ballast.  For a few dollars more get an electronic ballast and drop down to a 32 watt T8 bulb, which will cost a little more initally, but it will last longer, reduce energy costs and turn on and off like an incandescent bulb.  One warning though, don't use these around reptiles.  The frequency that these ballasts and bulbs operate at creates a strobe effect to reptiles and will drive them insane.  Consult a pet store if you're looking for something to use around reptiles.
527484
60 watts x 24hrs = 1440WHr\n= 1.44KWH
27524
400 Watt should do fine.  If you have more then 2 hard drives, go to 450 Watt.
370248
This is a nice problem.\n\nSwitch on one of the bulbs and wait for it to heat up. Turn in off and switch another one. Go downstairs, and feel the hotness. The hot bulb corresponds to the first switch and the one that is on the second switch. The one that is off is for the switch that has not been touched.
355313
Two, but it is very hard to get them into the bulb.
1079558
they work well.  I live in PA, and there is not much sunlight for most of the winter.  Wegmans, and most health food stores carry the light bulbs.  They are generally billed a "full-spectrum light bulbs."  \nNone of my family have SAD, however I definitely notice the mood change in my family when I buy them.