What is frequency?

Answer 1

A real good movie!

Answer 2

Frequency is the measurement of the number of times that a repeated event occurs per unit of time. It is also defined as the rate of change of phase of a sinusoidal waveform.

To calculate the frequency of an event, the number of occurrences of the event within a fixed time interval are counted, and then divided by the length of the time interval.

In SI units, the result is measured in hertz (Hz), named after the German physicist Heinrich Rudolf Hertz. 1 Hz means that an event repeats once per second, 2 Hz is twice per second, and so on. This unit was originally called a cycle per second (cps), which is still used sometimes. Other units that are used to measure frequency include revolutions per minute (rpm) and radians per second (rad/s). Heart rate and musical tempo are measured in beats per minute (BPM).

An alternative method to calculate frequency is to measure the time between two consecutive occurrences of the event (the period) and then compute the frequency f as the reciprocal of this time:


where T is the period. A more accurate measurement takes many cycles into account and averages the period between each.

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Frequency of waves
Frequency has an inverse relationship to the concept of wavelength. The frequency f is equal to the speed v of the wave divided by the wavelength λ (lambda) of the wave:


In the special case of electromagnetic waves moving through a vacuum, then v = c, where c is the speed of light in a vacuum, and this expression becomes:


When waves travel from one medium to another, their frequency remains exactly the same — only their wavelength and speed change.

Apart from being modified by the Doppler effect, frequency is an invariant quantity in the universe. That is, it cannot be changed by any physical process unlike velocity of propagation or wavelength.

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Examples
The frequency of the standard pitch A above middle C is usually defined as 440 Hz, that is, 440 cycles per second (Listen (help·info)) and known as concert pitch, to which an orchestra tunes.
A baby can hear tones with oscillations up to approximately 20,000 Hz, but these frequencies become more difficult to hear as people age.
In Europe, the frequency of the alternating current in mains is 50 Hz (close to the tone G), however, in North America, the frequency of the alternating current is 60 Hz (close to the tone B flat — that is, a minor third above the European frequency). The frequency of the 'hum' in an audio recording can show where the recording was made — in Europe or in America.

Answer 3

The number of waves passing through a point in 1 second is called frequency.

Answer 4

Frequency is the measurement of the number of times that a repeated event occurs per unit of time. It is also defined as the rate of change of phase of a sinusoidal waveform.

To calculate the frequency of an event, the number of occurrences of the event within a fixed time interval are counted, and then divided by the length of the time interval.

In SI units, the result is measured in hertz (Hz), named after the German physicist Heinrich Rudolf Hertz. 1 Hz means that an event repeats once per second, 2 Hz is twice per second, and so on. This unit was originally called a cycle per second (cps), which is still used sometimes. Other units that are used to measure frequency include revolutions per minute (rpm) and radians per second (rad/s). Heart rate and musical tempo are measured in beats per minute (BPM).

An alternative method to calculate frequency is to measure the time between two consecutive occurrences of the event (the period) and then compute the frequency f as the reciprocal of this time:
f=1/T , WHERE T =TIME PERIOD

where T is the period. A more accurate measurement takes many cycles into account and averages the period between each.

Frequency has an inverse relationship to the concept of wavelength. The frequency f is equal to the speed v of the wave divided by the wavelength λ (lambda) of the wave.
IT IS ALSO,
120*F/P=RPM , IN CASE OF GENERATORS.SO FOR A PARTICULAR FREQUENCY PREVAILING IN YOUR COUNTRY , YOU HAVE TO ADJUST THE RPM OF I.C. ENGINE AS POLES ARE CONSTANT.

Answer 5

Frequency can be expressed in many ways.

The most common unit we use is Hertz (Hz), which, as mentioned above is complete cycles (a wave or pendulum for example going all the way one way and then all the way back) per second.

In automotives and other engines, frequency is expressed in RPM, revolutions per minute.

Scientists also talk about angular velocity, in degrees or radians per second. It's easy to translate these to Hz, simply by dividing °/sec by 360 or rad/sec by 2 and then divide by pi (~3.1415926).

If you divide 1 by the frequency, you get the period, (the period of time required to complete one cycle).

Answer 6

Frequency is the number of vibrations made per second

Answer 7

Here is an example: if you go to the bathroom once every 3 hours then you the frequency with which you go to the bathroom would be 8 times a day.

Answer 8

the number of vibration of something about a constant point in every second is frequency . or we say the number of waves that pass through a point is frequency .

Answer 9

Frequency according to Mathematics & Physics. The number of times a specified periodic phenomenon occurs within a specified interval, as: The number of repetitions of a complete sequence of values of a periodic function per unit variation of an independent variable. The number of complete cycles of a periodic process occurring per unit time. The number of repetitions per unit time of a complete waveform, as of an electric current.

Frequency according to Statistics.
The number of measurements in an interval of a frequency distribution. The ratio of the number of times an event occurs in a series of trials of a chance experiment to the number of trials of the experiment performed.

Answer 10

Frequency is the measurement of the number of times that a repeated event occurs per unit of time. It is also defined as the rate of change of phase of a sinusoidal waveform.

Wikipedia is your friend.
http://en.wikipedia.org/wiki/Frequency

Answer 11

imagine a series of waves in the water.
The tops of the waves are called crests
The number of crests that pass a certain point in a unit of time
(typically second) is the frequency
FM radio is differentiated by changing the frequency of the radio signal generated