why is it 60 Hz in USA and 50 Hz in Europe?
602130
This happened so long ago to suggest there should have been a standard is funny.  The frequency has more to do with the speed of the turbine and the number of poles on the generator.  Early US generation was actually 25Hz.  The larger the frequency the smaller the transformers and motors are, but also the higher the losses (inductive reactance is proportional to frequency).  So there isn't necessarily a perfect frequency to use.
742865
It sets an upper limit to the frequency spectrum that can be controlled (Nyquist aliasing effect)\n\nIt affects the computational burden of the controller\n\nIt affects the hardware performance requirements of the sampling system\n\nThere are tradeoffs that can be made between data acquisition accuracy and sampling rate, using digital filtering techniques
1074275
Maybe in Europe, not in the US!
782134
You have to have a monitor that supports higher resiolution. Some of the monitors also supports higher monitor drivers under 60 Hz.
187108
The voltage and frequency of alternating current (AC) electricity used in homes varies from country to country throughout the world. Typically either 110-volt AC (110V) or 220-volt AC (220V) are used. Note that 110 volts and 220 volts are averages, since the voltage does fluctuate during usage. Most countries use 50Hz (50 Hertz or 50 cycles per second) as the frequency of their AC. Only a handful use 60Hz. The United States uses 110V and 60Hz AC electricity.\nHow values were selected\nThe type of electricity delivered to homes and businesses was first direct current (DC) but then changed to AC electricity. The standard voltage level started at 110V, went to 240V, back to 110V, and then to 220V. The frequency started at 60Hz and then went to 50Hz in most areas.
432038
Probably the only place (online, anyway) in Europe that might have it: http://overclockers.co.uk/
77677
Each device operates at a different frequency, just like a video card operating at 65mhtz, or a faster one at 72 mhtz. If one is operating at a different frequency (cant see it with the naked eye) then it will show up as a distortion. Just like having two music notes that are not harmonious with each other they cause distortion or in the parady given a bad chord.
504290
The RMS (root-mean-square) value of AC voltage is NOT dependant on the frequency.  For a sine wave, it is .707 (half the square root of 2) multiplied by the peak voltage.\n\n120 and 240 volt circuits common in the US are derived from the center-tapped transformer, the center called the neutral.  This gives you 120V between each phase and neutral, and 240V between the phases.  An analogy that might make more sense is with batteries.  You can put two 9V batteries in series to get 18V, but you still have 9V across each battery.\n\nI think what you want to know from your question, is why do we have both 120V and 240V.  You can argue 120V is safer than 240V, but it is more historical that 110-120V is used in the US (many other countries, but not all, use 220-240V).  The reason for having 240V for some equipment is with a higher voltage it will draw less current, so smaller wires can be used.  Similar to power transmission using high voltages.\n\nThe safety ground, the 3rd round pin on a normal plug, is connected to the neutral at the electrical service.  The neutral is grounded (to the earth), and so is the safety ground, but that connection to the earth has nothing to do with its purpose.  This safety ground connects metal parts of equipment to the neutral, so if a fault in the equipment causes voltage on those metal parts, it will trip the circuit breaker rather than give you a shock (if you were touching it WHEN the fault occurred, you could get a shock before the circuit breaker tripped).  Another thing about the safety ground, it never carries current under normal conditions, and for that to be true it can only be connected to the neutral at the service.  NEVER connect a safety ground to a neutral at another point.\n\nAlso, never take the cover off your circuit breaker or fuse panel if you don't know what you are doing.  Suggesting someone take off the cover and poke around with a fluke is a bad idea.
752428
Generally from 20 - 20,000 HZ depending on the individual. We lose some high end range as we age
510406
315mHz \n\nLove,\nKenneth Horowitz
10500
I think the previous answer is geared towards channel allocation and not bit rate vs bandwidth.  I will try to clarify the issue.\n\nFirst, you must understand how FM works and how a digital signal converts to FSK (frequency shift keying).  Therefore I will use a simple example.\n\nEach bit takes up some frequency.  For example, the bit '1' could take up 5 Hz carrier frequency on the bandwidth spectrum and '0' could take up 6 Hz on the bandwidth spectrum.  Therfore, there is a seperation of 1 Hz between bits.  \n\nIf I send a '1' followed by a '0' then on a meter I should see 5 Hz freqency and then a 6 Hz frequency back to back.  We could speed this up to infinity and therefore have these 2 frequencies transmitting all data at infinite speeds.\n\nIn the real world however, a '1' may fall around the 5 Hz frequency but not exactly on it.  It may be about 5 Hz.  Why around 5 Hz and not exactly on it everytime?  Because in the real world we have noise in transmission lines.  Noise can distort the frequency causing it to be a little less than 5 Hz or a little more than 5 Hz.  Imagine if the '1' bit is transmitted but on the receiving end it ends up receieved as 5.5 Hz.  What happens now?  It's not quite 5 Hz and it's not quite 6 Hz.  Noise caused it to move 0.5 Hz away from 5 Hz.  It is in the middle of 5 Hz and 6 Hz.\n\nNow the receiving end has to decide if this is '1' or '0'.  What are the odds the receiving end gets it right?  By slowing down the speed the 1s and 0s that are transmitted , you can hold steady the 5Hz or 6 Hz for that bit.  The faster you go, the less accurate the bit will fall exactly where it should on the frequency.\n\nSo, what are some possible solutions?  Well, you can slow the frequency down or make the frequency seperation larger.  For example, make a '1' be 5 Hz and make '0' be 10 Hz.  Now you have 5 Hz seperation between bits instead of 1 Hz seperation.  Now if the frequency of 5.5 Hz is received, the receiving end can determine that this should have been 5 Hz.  It's highly unlikely it was originally transmitted at 10 Hz.  Therefore, the receiving end detects a '1'.  \n\nBut what have you lost by doing this increase in frequency seperation?  You have taken up more bandwidth.  Every cable has only so much bandwidth and if you have several channels on a cable all transmitting at the same time, you need to limit the amount of bandwidth each channel takes up or you will run out.\n\nSo, therefore, since most companies don't want to backdown on speed to the consumer (you), then they upgrade their technology (i.e. cables) to higher bandwidth cables such as fiber optic cables.\n\nI hope this helped.  Others, please feel free to expand on this topic.  I've only discussed FSK modulation.  Other techniques such as PSK, ASK, QPSK, bit stuffing, NRZI, CRC, and FEC codes can improve bit rate over channels.\n\nYou can read more about bandwidth limits.  Shannon and Hartley came up with a theorem which still holds today and is used quite extensively.  I even know someone who worked with Shannon at Bell Labs back in the day.  Shannon's theorem is C = BW*log2(1+S/N) where C is the channel capacity in bits per second,  BW is bandwidth, S is the signal power and N is the noise power.\n\nWF\nTelecom Engineer
339135
first one is quite correct but frequency is in per second\n\n47 waves/min = (47/60)Hz   (1 Hz= 1wave/sec)
615599
Operating 60Hz appliances at 50Hz or viceversa may result in excessive heat buildup in transformers or in certain types of electric motors. \nIf you wish to safely operate 115V 60Hz appliances at 115V 50Hz then the following steps can be attempted: \n\nContact the manufacturer of the appliance. It may be possible to safely operate at 50Hz with the manufacturer's approval. \n\nSee if an alternate 240V 50Hz or 115V 50Hz power supply or electrical motor is available. Some manufacturers sell the same appliance or electric tool in many countries around the world and may be able to retrofit the power supply or electrical motor to 240V 50Hz. Some regions of Japan have 100V 50Hz supplies while others have 100V 60Hz supplies so it is not uncommon for Japanese manufactured electrical devices to have 50Hz solutions. \n\nIt is possible to purchase 60Hz sine wave power systems that take 240V 50Hz on input and produce 115V 60Hz on output. These solutions are generally very expensive, and it is usually more cost effective just to replace the tool or appliance. See here for a high current frequency conversion solution. \nIf these solutions, for one reason or another, do not work then there are only two further choices: dispose of the appliance or tool, or attempt to operate the appliance or tool at 50Hz and in the process potentially create a situation where the power supply or the motors in the appliance or tool are rendered non-operational.
257552
it could be because it is an old monitor. but there are many other reasons. bend prong, reverse pollaritys, has it been dropped, is it at room temperature, is there a lot of humitity
1029477
Frequency = Number of Cycle per Second\n\nThe unit of measure is in Hertz (Hz)\n\nFor example, our A.C. power line is 120V/60Hz and in some countries 240V/50Hz\n\nThe Musical Metronome also counts the number of beats per second, for example 60 beats per second.
698161
No, the voltages are different
649649
old tv flickers. plasma tv and some newer tv less flicker /dont hurt our eyes cause their frequency is 100hz or above.