Can I make my own EMF meter?
438682
sure. go to a science store or look up schematics on the web.
292991
http://www.scitoys.com/scitoys/scitoys/echem/echem3.html#sflatpanel\nHere is a site that uses household type apparatus. simple and says it delivers some current. \n\nhttp://www.solideas.com/solrcell/english.html \nhere is another without household items but you can order the kit on here.
152758
The measure magnetic fields with a magnetometer.
734023
It sounds like you need a multi-meter which is handy for all your electric household needs. You can measure current with most of these and they can be found in hardware stores like Ace in most cases and possible even at places like Wal-Mart. They are not uncommon items. If you want you might be able to go online and search for a amp meter most likely from a physics teacher website. I'm sure your nearest hardware store will carry coil but if not, Radioshack is an option. Problem with Radioshack that I have had is too much money for too little quantity (this is in general and not specific to the coils) if you have time, you can browse the internet for teacher selling sites but you may have to pay for shipping which might also run up the cost. The magnets really depend on what scale you are talking about. Hobby Stores will definitely carry small craft magnets but if you need really strong magnets your best bet is once again a teacher website. I hope that I have been at least some use to you, and best of luck on your experiment/project.
738167
Unless you are playing with low voltage, please find some other project. 120 Volt or 220 volt is very dangerous.\n\nAny way you will need all the components in same voltage I say get every thing in under 9 volts to make things easy, they must operate in 6 to 8 volt range so you will have voltage to spare. You may not be able to find them readily.\n\nThis is how it works.\n\nClapping sound is picked up by micro phone.\n\nThis produces a signal, that will close an open circuit on a lamp(or any thing that you need to turn on like a bell).\n\nTo make a package, like the one you buy in the store, it took quite a few years to perfect it, and they had experts working on it.. \n\n1.  9 volt battery. few to operate the systems.\n2.  red and black wire.\n3.  9 volt lamp.\n4.   6 volt Micro phone.\n5.   Sound activated switch, 6 volt \n6.   Tapes electrical.\n7.    cardboard to mount every thing.\n8.    cutting tool to make connections.\n9.    Solder iron and silver solder wire.\n10.   Different types of connectors.\n11.   Glue to put components on the board. \n\nEdmund-scientific.com may have a kit, it is on Internet.\n\nBuy the kit and assemble it.
445689
Radio shack has a book (about $20) that has every freq you could ever need in it , even your local #'s
1001873
Yes, you need a lab to do this! If that wasn't clear to you, this may not be the best project to try to copy!\n\nWhy not have an idea of you own, something you can do with what you have at hand at home? You might learn something!
719437
I don't know what your interests are, but one experiment that I have done in the past is building an electric motor.  It's easy and does not require a lot of equipment.  I'll include the equipment list below.  If you are interested, send me an email and I will send you a picture of the setup.  That would be easier than explaining it here.\nEquipment required:\n1)Small stable platform, like a wooden board (maybe like 6 inches long and 4 inches wide, and perhaps like 1/2 inch thick).  Maybe a piece of cardboard would work as well.\n2)Magnet (something like 1 inch by 1 inch and 1/2 inch thick)\n3)Copper wire with a small diameter (something you would be able to wrap around your fingers)\n4)6-Volt battery (might be called a lantern battery). The shape of the battery is rectangular and the battery terminals look like little springs at the top of the battery.\n5)Two paper clips\n6)Two thumb tacks
394827
yes you can. For real low freq. you can actually do a DC measurement. Just slow the sweep rate way down and you will see it.
443133
hi,\n\ntransformers you can buy for pretty cheap at any decent electronics or  hobby stores (radio shack sucks these days, but they probably still have them).  \n\nhowever you can make them really easily.  all you need is a hunk of steel or iron (some kind of rod-shaped thing would work, as would a donut-shaped loop).  take one wire and wind it around the piece of steel N times.  take another wire and wind it around a different part of the steel M times.  congratulations, you have just built a transformer that will step up/down voltages by a factor of M/N (or N/M, if you hook it up the other way.)\n\ncheers-
890360
I have already answered part 1. in another question you've asked. I think you probably didn't use the right units (like cm needs to be convered to meters) and got the wrong answer.\n\nNow for part 2:\n\nInduced EMF, ℰ = -L(di/dt)\n\nwhere i is the current and L is the inductance\n\nWe are given that the magnitude of the induced current,\n\ndi = 47 mA\n\nand the oscillation frequency is 100 Hz. This means that dt = 1/f = 0.01 sec\n\nWe have L = 8.44 × 10-^3 henries from before\n\nSo |ℰ| = L(di/dt) = -(8.44 × 10-^3)(0.047)/(0.01) = 0.0397 volts\n\n------------------------------------------------------\n\nNow part 3 has to do with mutual inductance:\n\nVs = VpNs / Np\n\nwhere \n\nVs is the voltage across the secondary inductor, \nVp is the voltage across the primary inductor (the one connected to a power source), \nNs is the number of turns in the secondary inductor, and \nNp is the number of turns in the primary inductor. \n\nTherefore Vp = VsNp/Ns and Vs = 0.0397 volts as calculated before, so\n\nVp = (0.0397)(197)/(2920) = 0.00268 volts
809563
Go to http://www.rosecitysoftware.com An download their DU Meter.  \n\nMinddoctor. France
991930
I hope that one of these will be what you are looking for.\n\nhttp://www.iesna.org/\nhttp://www.ewh.ieee.org/soc/ies/\nhttp://www.ielectric.com/Net/index.asp
823030
You could use a resistor in series for the voltmeter and a shunt resistor in parallel with the ammeter.  You can also use a signal amplifier to transform the input signal to one that is within the range of the meter.  If it is a panel type meter, do not forget to change the scale behind the meter.\n\nJeffM
935132
keep it far from electrodomestics\n\n:> peace\n.
1160573
e-mail me: intel_knight-at-yahoo-dot-com\n\nAnd I have no clue how to build that EMP thing, or if it is even possible. I just thought it would be a cool thing to have.
444083
If you move the magnet through the core of the solenoid, the fluxing magnetic field will induce an electric current in the wires which can be measured using the amp meter.