↳ Investigating the 'Mpemba Effect': Can Hot Water Freeze Faster than Cold Water?.↳ From Dull to Dazzling: Using Pennies to Test How pH Affects Copper Corrosion.↳ Forensic Science: Building Your Own Tool for Identifying DNA.↳ Electrolyte Challenge: Orange Juice vs.↳ Do Oranges Lose or Gain Vitamin C After Being Picked?.↳ Math & Computer Science Sponsored by Hyperion Solutions Corp.↳ Grades 9-12: Getting Ready for the Science Fair.↳ Grades 6-8: Getting Ready for the Science Fair.↳ Grades K-5: Getting Ready for the Science Fair.↳ Science Teachers: Fairs, Projects, and General Support.↳ Advanced Science Competitions (Intel ISEF, Intel STS, Siemens Competition, JSHS, etc.).↳ Grades 9-12: Math and Computer Science.↳ Grades 9-12: Life, Earth, and Social Sciences.↳ Grades 6-8: Math and Computer Science.↳ Grades 6-8: Life, Earth, and Social Sciences.↳ Grades K-5: Math and Computer Science.↳ Grades K-5: Life, Earth, and Social Sciences.Active Forums (Make all new posts here).Here is site which will give you a table as well as an interactive way of calculating db numbers. The difference in two db readings can be referenced easily to power ratios. For example, when dividing large numbers by small numbers (often in several decimal point precision) its easier to subtract one db level from another, which is the same as adding and subtracting exponents to multiply and divide as in scientific notation. The decibel scale makes it easier to manipulate these non-linear numbers. This makes it useful in sound measurement, as our hearing is very non-linear. Because it is a logarithmic scale, it is possible to express wide variations of power in small numbers. The use of the decibel scale is more to measure ratios of power or voltage over several magnitudes. Or 0 dB = 1 uV/m for electro-magnetic field strength Radio engineering: 0 dB = 1 mW in 50 Ohm impedence Television industory: 0 dB = 1 mV rms across 75 Ohm impedence (Measurements to this standards use the unit symbol dBm) Here are a few examples:Īudio industry: 0 dB = 1 mW in 600 Ohm resistance 0 db is just a reference point to compare to other measurements. In fact, various standards assign a measurable signal strength equal to 0 db. Primarily, an expression of Zero db does not necessarily mean 'zero' signal amplitude. Confusedcat - It's easy to understand your confusion, as the decibel can mean several things in several contexts.
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