can anybody tell what is the unit of frequincy?from whose name its unit is fixed?

Question

write his full name

Answer 1

One unit of frequency is Hertz named after Heinrich Rudolph Hertz. Another unit is cycles per second or cps. I got this information from Wikapedia on line encyclopedia.

Answer 2

Frequency is expressed as cycles per second.

Now a days we see this being expressed as KHz/sec or MHz/sec(kilo hertz or Mega Hertz per second)

This term is normally used in Alternating Current (A.C)

this term is expressed by symbol or letter 'f'.

In wave propagation,to say the cycles per second and in radio waves etc the term is used .

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 sometimes used. Other units that are used to measure frequency include revolutions per minute

Answer 3

From Wikipedia, the free encyclopedia
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For the radio pioneer after whom the physical unit was named, see Heinrich Rudolf Hertz. For other uses, see Hertz (disambiguation).

"MHZ" redirects here. MHZ may also refer to the IATA airport code for RAF Mildenhall.

The hertz (symbol: Hz) is the SI unit of frequency. Its base unit is cycle/s (also called inverse seconds, reciprocal seconds). In English, hertz is used as both singular and plural. As any SI unit, Hz can be prefixed; commonly used multiples are kHz (kilohertz, 103 Hz), MHz (megahertz, 106 Hz), and GHz (gigahertz, 109 Hz).

One hertz simply means one per second (typically that which is being counted is a cycle); 100 Hz means one hundred per second, and so on. The unit may be applied to any periodic event — for example, a clock might be said to tick at 1 Hz, or a human heart might be said to beat at 1.2 Hz. The frequencies of aperiodic events, such as radioactive decay, are expressed in becquerels.

To avoid confusion, periodically varying angles are typically not expressed in hertz, but rather in an appropriate angular unit such as radians per second. A disc rotating at 1 revolution per minute (RPM) can thus be said to be rotating at 0.105 rad/s or 0.017 Hz, where the latter reflects the number of complete revolutions per second. The conversion between Hz and rad/s is 2π rad/s = 1Hz.

Answer 4

The unit is hertz (number per second). It is named after Heinrich Rudolf Hertz.

Answer 5

It is Hz. (Cycle per second), named after the radio pioneer after whom the physical unit was named, Heinrich Rudolf Hertz

Answer 6

The unit of frequency is Hertz(Hz). It is named after the German scientist Hertz.

Answer 7

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Answer 8

Hertz

Heinrich Rudolf Hertz (1847-1894)

Frequencies in Hertz and Radians

A standard measure of frequency is Hertz, abbreviated Hz. It means "cycles per second."
By convention, frequencies in Hertz are usually written using the symbol f. For example, the frequencies of the musical note A on the piano keyboard are

f1 = 55, f2 = 110, f3 = 220, f4 = 440, f5 = 880, f6 = 1760, f7 = 3520, f8 = 7040

A sinusoidal waveform with frequency f4 = 440 can be defined by

x(t) = cos(2p f4 t)
Radians per second

The factor 2p in the expression above is a nuisance. The argument to the cosine function has units of radians, so 2p has units of radians/cycle. Explicitly showing all the units (in square brackets),

2p [radians/cycle] f4 [cycles/second] t [seconds] = 2p f4 t [radians]

To avoid having to keep track of the factor 2p everywhere, it is common to use the alternative units for frequency, radians per second. The symbol w is commonly used to denote frequencies in radians per second. The relationship between Hertz and radians per second is simple,

w = 2p f

Thus, in radians per second, the frequencies of the musical note A on the piano keyboard are

w 1 = 2p ´ 55, w 2 = 2p ´ 110, w 3 = 2p ´ 220, w 4 = 2p ´ 440,

w 5 = 2p ´ 880, w 6 = 2p ´ 1760, w 7 = 2p ´ 3520, w 8 = 2p ´ 7040
Discrete-time frequencies

When the domain of a signal is DiscreteTime = Integers, then the units of frequency are cycles/sample. Consider for example the discrete-time signal given by

" n Î DiscreteTime, x(n) = cos(2p f n).

Suppose this represents an audio signal that is sampled at 8000 samples/second. Then to convert f to Hertz, just watch the units:

f [cycles/sample] ´ 8000 [samples/second] = 8000f [cycles/second].

The frequency could have been equally well given in units of radians/sample, as in

" n Î DiscreteTime, x(n) = cos(w n).

To convert w to Hertz,

w [radians/sample] ´ 8000 [samples/second] ´ (1/2p ) [cycles/radian] = (8000w /2p ) [cycles/second].
Ranges of frequencies

An extremely wide range of frequencies are used by electrical engineers. The following abbreviations are common:

* kHz - kilohertz, thousands of cycles per second.
* MHz - megahertz, millions of cycles per second.
* GHz - gigahertz, billions of cycles per second.

Audible sounds signals are in the range of about 20 Hz. to about 20 kHz. Sounds above this frequency are called "ultrasonic." Electromagnetic waves range from less than one hertz (used speculatively in seismology for earthquake prediction) through visible light near 1015 Hz. to cosmic ray radiation up to 1025 Hz. See uses of electromagnetic radiation in communication.
Heinrich Hertz

Heinrich Rudolf Hertz (1847-1894), after whom the unit of frequency is named, was the first to transmit and receive radio waves. Both an experimentalist and a theoretician, Hertz rederived Maxwell's wave equations, which model the propagation of electromagnetic waves, casting them in the form used today. He eliminated Maxwell's unusual mechanical ideas about the role of the ether, which had impeded acceptance of his model. Between 1885 and 1889, while he was a professor of physics at Karlsruhe Polytechnic, he produced electromagnetic waves and measured their wavelength and velocity in the laboratory. He showed that the nature of their reflection and refraction was the same as those of light, supporting the theory that light waves are electromagnetic radiation obeying Maxwell's equations.

Source: Leonard S. Taylor's web page on historical figures in engineering.

Answer 9

HERTZ