Units & Notation
Click one of the buttons above to move to that topic.
|
Units & Notation
Click one of the buttons above to move to that topic.
|
|
Click here to read the lecture notes on this topic. Please take the practice quiz below. This is completely anonymous and no records of results are maintained.
If you do not see the quiz above your browser may not support Java Applets. You may wish to download an update for your browser. There are three Fundamental Units: length, mass, time. The most commonly used systems of measurement are English and metric systems. The metric (SI) system was developed scientifically. Length - meter, Mass - kilogram, Time - second The US passed the metric conversion act in 1975. The SI system has 7 base units: length, time, mass, electric current, temp, luminous density, and molecular substance.
SCIENTIFIC AND ENGINEERING NOTATION Scientific Notation Numbers expressed in Scientific Notation are represented as a number that is greater than or equal to 1.0 and less than 10 multiplied times 10 with an exponent that can be negative or positive. Any number may be represented this way. For example: 82,400 = 8.24 x 10 4 0.0033 = 3.3 x 10 -3 Various multiples and submultiples are assigned prefixes and symbols. The prefix "kilo" or symbol "k" is equivalent to a value times 10 raised to the third power. For example, 2000 = 2 x 10 3 = 2k. Engineering Notation Numbers expressed in Engineering Notation are represented as a number that is greater than or equal to 1.0 and less than 1000 multiplied times 10 with an exponent that is a multiple of 3 which can negative or positive. Any number may be represented this way. For example: 545,000 = 545 x 10 3 .0027 = 2.7 x 20 -3
PREFIX CONVERSION In electronics it is important to be able to convert a value represented in one prefix to another. For example, 1.5 mA is equal to 0.0015 A. ENTERING NUMBERS INTO THE CALCULATOR Most scientific calculators have an exponent key which may be labelled EE or Exp. Usually to represent 180 x 10 3 you would enter 180, press EE, and then 3. Some scientific calculators also have the ability to display the prefixes.
|