When replacing a light fixture, do I have to turn off the power to the house?
Yes it's that simple, how do you tell which switch, turn each breaker off till that light fixture goes off, then leave it off replace if you know how. Now that's simple if it turns out you don't know as much as you thought you did, and you sound like you do, then don't go any further call and electrician. Because it's simple and if you have problems then you don't know enough. lol didn't know there were so many answers and the last one was good too, I wouldn't have bothered:)
Does it waste electicity turning lights on and off?
Because I want to save electricity I always turn lights off when I leave a room. But I've heard that it wastes A LOT of electricity turning lights on (like, it uses up a lot of electricity to kick start the lights) ... so it's a good idea to just keep lights on in rooms if you are still sort of using them. So which is better?
What does Darth Vader mean by: “You don't know the power of the dark side”?
The first time Vader says this is in The Empire Strikes Back. He’s leading in to the big reveal. He knows that Luke is his son and that Obi-Wan probably hasn’t told him what actually happened. He doesn’t know exactly what Luke was told, but can guess it probably wasn’t “turned to the dark side and became Darth Vader.” He’s not threatening or bragging here, he’s building up to the notion that the dark side is so powerful it made him what he is, turned a powerful Jedi into a Dark Lord of the Sith. Luke doesn’t realize how strong he could become and how tempting it is if he gives in. If anything, he’s sort of tempting—”I just beat you and your light side down, I wiped out all the Jedi, and how did I do that? Dark side. Look what you could become. Look what WE could do.” Remember, he follows up the big reveal by trying to recruit Luke to take down the Emperor and rule the galaxy together. He’s telling Luke that the Dark side IS stronger, look what it could do for you, we could do what you want—you can’t take down the Emperor by being good, but the dark side is powerful.In Return of the Jedi when he repeats the line, now he’s sort of defending himself. Disobey the Emperor? Luke doesn’t understand how strong the dark side is once you embrace it. Vader has gone dark, and doesn’t see how he can ever resist it and turn back. The dark side’s influence is just too strong. It’s too late for him. This is continuing the Vader we see at the end of ESB when the Falcon escapes—instead of strangling the nearest officer for failing, Vader is too stunned to react. He starts second-guessing-how could Luke walk away? If he could, why can’t Vader? The dark side is just too strong, once you’re deep in it, he decides.
How much energy does it take to turn a light bulb on, as compared with keeping it on? How does this vary between light bulbs?
This question is a bit mis-phrased. The energy required to turn on a bulb makes sense. The energy required to keep a bulb on does not make sense -- you are talking about power, not energy, i.e. the energy per unit time. (Your bulb requries a certain amount of energy to turn on -- that's fine, but what are you comparing it to? The energy to keep a bulb on for 1 minute? 10 minutes? 1 hour?)Chances are, for your average time you're using a bulb in one sitting (say, at the very least 10 minutes), the energy required to turn it on is negligible. Unless you're turning your bulbs on and off several times a second (say, in some PWM-controlled scenario) I think you do not need to worry about that energy consumption at all compared to the time you use it for normal use. However, as others have pointed out, you may destroy the life of the bulb by turning it on too frequently if it is a CFL -- which has nothing to do with energy usage, but rather just wear and tear.
How can I make sure my refrigerator light is turning off when I close the door?
Touch it immediately after opening the door, if it is hot it has been on. Alternatively put a Yakaduchimalain magician inside and ask him to loosen it when you close the door, don't worry he wont suffocate.
Does it take more electricity to turn the t.v on and off several times a day or just leaving it on constantly?
The power surge created when turning the T.V. on will equate to a minute at the max of run time, more likely 30 seconds, so unless you are leaving the room for less then a minute it will be more efficient to turn it off.
I want a switch but I don't know what it is called?
It's called a dimmer (the actual part of the dimmer that the knob turns is called a rheostat or potentiometer). It can also be a just a rheostat, and not a dimmer circuit controlled by a potentiometer. A rheostat can be used as a light dimmer, though it's inefficient (instead of using less electricity on dim settings, it just divides the energy between itself and the lights and radiates out the difference as heat). But for low-current lights such as on an instrument panel, that's OK, so they are used for dashboard lights. But I'm thinking you have some lights that draw more current than dashboard lights. I found a couple of 12 volt dc dimmers in a web search that may work for you: One is designed for RV 12-volt lighting (either incandescent or LED) and costs $20 (with free shipping): https://www.pca.com/newproducts/12vdimme... EPL1012 is the one on that page to get -- the EPL1010 on that page is rated at lower power (18w vs. 60w) and can not be used with LEDs (and the EPL1012 can)! The other is designed for LEDs only, but costs a lot less,$4.74 (including $0.50 for shipping): http://www.amazon.com/Dimmer-Brightness-... So if the lights you put in your truck are LEDs you could use that. Sometimes the device is called a "dimmer switch," but simply searching AutoZone for a "dimmer switch" comes up with the kind of swich that switches between low and high headlight beams, which isn't what you want. Searcing AutoZone for an "instrument cluster dimmer switch" WILL get you to the rheostats that dim the dashboard lights, but they try to find you an exact fit by vehicle, which also may not be what you want.