advertisement

T5 Electrical principles, math for electronics, electronic principles, Ohm’s Law [4 Exam Questions - 4 Groups] Chapter 3A Electrical Terms Voltage is the electromotive force (EMF) that causes electron flow The volt is the basic unit of electromotive force (EMF) Electrical current is measured in Amperes Current is the flow of electrons in an electric circuit Direct Current flows only in one direction? Alternating Current reverses direction on a regular basis Electrical power is measured in Watts Power describes the rate at which electrical energy is used Copper is a good electrical conductor Glass is a good electrical insulator A mobile transceiver usually requires 12 volts Electrical Units Hertz is the unit of frequency Capacitance is the ability to store energy in an electric field Farad is the basic unit of capacitance Inductance is the ability to store energy in a magnetic field The Henry is the basic unit of inductance RF is the abbreviation that refers to radio frequency signals of all types Radio waves is electromagnetic waves that travel through space Math Units MEGA = 1,000,000 Million KILO = Thousand 1,000 MILLI = 0.001 1/1,000 MICRO = 0.000,001 1/1,000,000 PICO = 0.000,000,000,001 1/1,000,000,000,000 Decibel (dB) +3 dB = 2X -3 dB = X/2 +6 dB = 4X -6 dB = X/4 +10dB = 10X Ohm’s Law E = I x R Voltage = Current x Resistance I = E / R Current = Voltage / Resistance R = E / I Resistance = Voltage / Current P = E x I Power = Voltage x Current I = P / E Current = Power / Voltage ~ Page 1