Learn DECADE Strategy. Get access to the proven and revolutionary DECADE Strategy immediately on your phone through the DECADE app. Learn how tournament winners manage their game by optimizing course strategy. Watch the DECADE Strategy Tutorial on any device anywhere and learn what Tour Pros and Amateurs are doing to win golf tournaments. Decade definition: A decade is a period of ten years, especially one that begins with a year ending in 0. Meaning, pronunciation, translations and examples Log In Dictionary. Nov 28, 2019 According to Emily Brewster, a senior editor at Merriam-Webster, a decade in popular culture is not defined by scientific convention. Because of this, the 2020s will begin on Jan. 1, 2020, and end.
Three decades: 1, 10, 100, 1000 (100, 101, 102, 103)
Three decades: One thousand 0.001s, one-hundred 0.01s, ten 0.1s, one 1.
One decade (symbol dec[1]) is a unit for measuring frequency ratios on a logarithmic scale, with one decade corresponding to a ratio of 10 between two frequencies (an order of magnitude difference).[2][3] It is especially useful when describing frequency response of electronic systems, such as audio amplifiers and filters.
A closely related unit is the octave, which corresponds to a ratio of 2 between two frequencies.
Calculations[edit]
The factor-of-ten in a decade can be in either direction: so one decade up from 100 Hz is 1000 Hz, and one decade down is 10 Hz. The factor-of-ten is what is important, not the unit used, so 3.14 rad/s is one decade down from 31.4 rad/s.
To determine the number of decades between two frequencies ( & ), use the logarithm of the ratio of the two values:
What Is A Decade
- decades[2][3]
or, using natural logarithms:
- decades[4]
- How many decades is it from 15 rad/s to 150,000 rad/s?
- dec
- How many decades is it from 3.2 GHz to 4.7 MHz?
- dec
- How many decades is one octave?
- One octave is a factor of 2, so decades per octave (decade = just major third + three octaves, 10/1 (Play) = 5/4)
To find out what frequency is a certain number of decades from the original frequency, multiply by appropriate powers of 10:
- What is 3 decades down from 220 Hz?
- Hz
- What is 1.5 decades up from 10?
To find out the size of a step for a certain number of frequencies per decade, raise 10 to the power of the inverse of the number of steps:
- What is the step size for 30 steps per decade?
- – or each step is 7.9775% larger than the last.
Graphical representation and analysis[edit]
Decades on a logarithmic scale, rather than unit steps (steps of 1) or other linear scale, are commonly used on the horizontal axis when representing the frequency response of electronic circuits in graphical form, such as in Bode plots, since depicting large frequency ranges on a linear scale is often not practical. For example, an audio amplifier will usually have a frequency band ranging from 20 Hz to 20 kHz and representing the entire band using a decade log scale is very convenient. Typically the graph for such a representation would begin at 1 Hz (100) and go up to perhaps 100 kHz (105), to comfortably include the full audio band in a standard-sized graph paper, as shown below. Whereas in the same distance on a linear scale, with 10 as the major step-size, you might only get from 0 to 50.
Bode plot showing the concept of a decade: each major division on the horizontal axis is one decade
Electronic frequency responses are often described in terms of 'per decade'. The example Bode plot shows a slope of −20 dB/dec in the stopband, which means that for every factor-of-ten increase in frequency (going from 10 rad/s to 100 rad/s in the figure), the gain decreases by 20 dB.
See also[edit]
Sources[edit]
What Is A Decade Mean
- ^ISO 80000-3:2006 Quantities and Units – Space and time
- ^ abLevine, William S. (2010). The Control Handbook: Control System Fundamentals, p. 9-29. ISBN9781420073621.
- ^ abPerdikaris, G. (1991). Computer Controlled Systems: Theory and Applications, p.117. ISBN9780792314226.
- ^Davis, Don and Patronis, Eugene (2012). Sound System Engineering, p.13. ISBN9780240808307.
What Is 20 Years Called
Retrieved from 'https://en.wikipedia.org/w/index.php?title=Decade_(log_scale)&oldid=924639756'