AC & DC Circuits Flashcards
Tera
12
Giga
9
Mega
6
Kilo
3
Milli
-3
Micro
-6
Nano
-9
Pico
-12
Ohm’s Law
V = IR, I = V/R, R = V/I
Wattage
V x I
Doping
The introduction of impurities into a semiconductor crystal to the defined modification of conductivity
Doping
The introduction of impurities into a semiconductor crystal to the defined modification of conductivity
Coulomb (C)
Is the standard unit of electric charge (Q) in the International System of Units
EMF
Electromotive Force (E); the unit of which is the Volt (V)
Potential Difference
The voltage between two points
Joule
Unit of Work
Hole
The positive charge remaining when a valence electron detaches
Resistance Colour Code
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Integrated Circuit
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Tolerance
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R = pL/A
Formula for calculating Resistance - Material Resistance (measured in ohm-meters or ohm-centimeters) multiplied by Length of object, divided by cross-sectional Area
R = R20(1 + a20(t - 20))
Formula for calculating Resistance when the temperature is less or greater than 20 degrees celsius. ‘a20’ is a material’s temperature coefficient.
dV/dt
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Voltage Drop
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1 Horsepower
746 Watts
Efficiency (η)
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Kirchoff’s Voltage Law (KVL)
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Load
Device(s) within a circuit which draw electricity
Kirchoff’s Current Law (KCL)
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CDR
Current Divider Rule
VDR
Voltage Divider Rule
Meter Loading
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AM (Amplitude Modulation)
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FM (Frequency Modulation)
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Capacitive Reactance
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Dielectric
The insulation material between a capacitor.
Stray Frequency
A problem with capacitors in high frequency AC circuits
Permittivity
The ability of a substance to store electrical energy in an electric field. The ease with which lines of electrical flux are
Farad (Unit)
The unit of capacitance
Transient
A momentary pulse of current from a capacitor at the instant of switch closure
Mutual Capacitance
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Time Constant (τ)
The time constant, τ is found using the formula T = R x C in seconds.
Decay Equation
Vr (Resistor Voltage) = E(e^-t/τ)
Growth Equation
Vc (Capacitor Voltage) = E(1 - e^-t/τ)
Discharge Equations
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Compound/Combination Circuit
A circuit using a combination components in both series and parallel
Polar Form
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Rectangular Form
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Phasor Form
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Formula for Current across Capacitor
Ic = Q/t = EC/t
Current equals Coloumbs divided by seconds, or Voltage times Capacitance divided by seconds.
Inverter and Rectifier
An inverter and a rectifier perform opposite functions in electronic circuits. Both act as electric power converters; a rectifier changes current from alternating current (AC) to direct current (DC), while an inverter converts DC to AC.
Admittance
Admittance is the reciprocal of impedance, Z and is given the symbol Y. In AC circuits admittance is defined as the ease at which a circuit composed of resistances and reactances allows current to flow when a voltage is applied taking into account the phase difference between the voltage and the current.
Capacitive and Inductive Susceptance
Susceptance is the reciprocal of of a pure reactance, X and is given the symbol B. In AC circuits susceptance is defined as the ease at which a reactance (or a set of reactances) allows an alternating current to flow when a voltage of a given frequency is applied.
Resonance
Electrical resonance occurs in an AC circuit when the two reactances which are opposite and equal cancel each other out as XL = XC and the point on the graph at which this happens is were the two reactance curves cross each other. … This is because at resonance they are cancelled out.
Tuned Circuit
An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together.
Q Factor
In physics and engineering the Quality Factor or Q Factor is a dimensionless parameter that describes how underdamped an oscillator or resonator is. It is defined as the ratio of the peak energy stored in the resonator in a cycle of oscillation to the energy lost per radian of the cycle.
Apparent Power
The combination of reactive power and true power is called apparent power, and it is the product of a circuit’s voltage and current, without reference to phase angle. Apparent power is measured in the unit of Volt-Amps (VA) and is symbolized by the capital letter S
Volt-Ampere
A volt-ampere is the unit used for the apparent power in an electrical circuit. The apparent power equals the product of root-mean-square voltage and RMS current. In direct current circuits, this product is equal to the real power in watts. Volt-amperes are useful only in the context of alternating current circuits.
Duty Cycle
A duty cycle is the percentage of the waveform that occurs above the zero axis. The duty cycle of a square wave is always 50%, or 1/2. Because the duty cycle is 1/2, every second harmonic is not present.
Fractional Frequency
f2-f1/fs = 1/Qs
Power Factor Correction
Power-factor correction increases the power factor of a load, improving efficiency for the distribution system to which it is attached. Linear loads with low power factor (such as induction motors) can be corrected with a passive network of capacitors or inductors.
Compensated and Uncompensated
The current after and before Power Factor Correction
Quality Factor
Reactive Power / Real Power = I^2 * X / I^2 * R = X / R
Bandwidth Formula
Frequency / Quality Factor = f / Q
