Introduction to Electrical Computer Engineering Units Scientific Notation

Introduction to Electrical & Computer Engineering Units & Scientific Notation Dr. Cynthia Furse University of Utah 1

Introduction to Electrical Engineering Units & Scientific Notation • Review the UNITS we will be using • Review Scientific Notation • Convert 2

International System of Units (SI) Dimension Unit Symbol Relationship Length Meter m Mass Kilogram kg Time Seconds s Temperature Kelvin K Voltage Volt V Current Ampere A Charge Coulomb C =(A)(s) Resistance Ohm Ω =V / A Capacitance Farad F = C / V Inductance Henry H = (V)(s) / A Power Watt W =(V)(A) Frequency Hertz Hz = 1 / s 3

Prefixes & Scientific Notation Prefix Symbol Magnitude exa E 1018 atto a 10 -18 peta P 1015 femto f 10 -15 tera T 1012 pico p 10 -12 giga G 109 nano n 10 -9 mega M 106 micro µ 10 -6 kilo k 103 milli m 10 -3 4

Typical Naming Conventions • General use: Lower case letters i v or i v may or may not be time varying • Time varying (t) i(t) and v(t) are time varying (not constant) • Not time varying (DC): capital letters I V are DC (constant) values • Bold: Something special (matrix, vector, phasor version of i(t), Laplace or Fourier Transform, etc. ) I V 5

From Units to Scientific Notation -3 • 1 m. V = 1 x 10 V 6 • 1 MV = 1 x 10 V From Scientific Notation to Units 6 6 • 1 x 10 V / 10 = 1 MV -3 -3 • 1 x 10 V / 10 = 1 m. V 6

From one Unit to Another • 7

Conclusion: Units & Scientific Notation • Review the UNITS we will be using • Review Scientific Notation • Convert from one unit to another 8

Delicate Arch, Arches National Park, near Kanab, Utah 9

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