AC CIRCUITS Flashcards
it is form of electricity that flows in an alternating directions and/or possessing a voltage with alternating polarity over time.
-ALTERNATING CURRENT
the shape of a graph of the varying quantity against time or distance is called
-WAVEFORM
the standard ac waveform is the
-SINE WAVE
is the number of cycles in one second.
-FREQUENCY
the length of time is takes to complete one cycle. It is basically the reciprocal of the frequency.
-PERIOD
is the distance between two points of similar cycles of a periodic wave.
-WAVELENGTH
the value of the wave at its peaks.
-AMPLITUDE
is the value of a sine wave at any instant of time or at any angle rotation. It is denoted by a lowercase letters v and i for voltage and current repectively.
-INSTANTANEOUS VALUE
is the maximum value denoted by Vm or Vp for voltage and Im or Ip for current.
-PEAK VALUE
is the arithmetic average of all the values in a sine wave for 1 half-cycle.
-AVERAGE VALUE
value of an alternating sine wave is the value that gives the same heating effect as a steady direct current or voltage source.
-ROOT MEAN SQUARE
rms is also considered as
-EFFECTIVE VALUE
is the ratio of the rms value to the average value.
-FORM FACTOR
is the ratio of peak value to the rms value.
-PEAK FACTOR
phase is an angular measurement that specifies the position of a sine wave relative to a reference.
-AC PHASE RELATIONSHIP
is defined as one waveform that is ahead of another in its zero crossing on the horizontal axis. Sine wave is shifted to left or reference by angle.
-LEADING WAVEFORM (PHASE SHIFT SINE WAVE)
is one that is behind another. Sine wave shifted to the right of reference by an angle.
-LAGING WAVEFORM (PHASE SHIFT SINE WAVE)
is a rotating arrow used to represent the time varying quantities in terms of their magnitude and angular measurements.
-PHASOR
is the total opposition to ac current with the resistance and total reactance of the circuit combined.
-IMPEDANCE
gives the angle between the total voltage and current in AC circuit.
-IMPEDANCE ANGLE
is the opposition to ac current other than resistance due to inductance and/or capacitance in the circuit . It is dependent on the frequency of the ac source.
-REACTANCE
is the opposition to alternating current in a capacitor. It varies inversely with the frequency of the ac source.
-CAPACITIVE REACTANCE
is the opposition to alternating current in a inductor. It varies inversely with the frequencny of the ac source.
-INDUCTIVE REACTANCE
is the opposition to ac current by the same factor as in dc in resistive circuits.
-RESISTANCE
the reciprocal of impedance in seiemens, the over all ability o an electric circuit to pass alternating current.
-ADMITTANCE
the ability of the inductance and capacitance to pass ac in siemens the imaginary component of admittance.
-SUSCEPTANCE
the ability of an inductor to permit current to flow.
-INDUCTIVE SUSCEPTANCE
the ability of a capacitor to permit the flow of current.
-CAPACITIVE SUSCEPTANCE
the current always lags behind the voltage by 90 electrical degrees. remember ELI
-PURELY INDUCTIVE REACTANCE
the current always leads the voltage by 90 electrical degrees. remember ICE
-PURELY CAPACITIVE CIRCUITS
the product of RMS value ofthe voltage and current.
-APPARENT POWER
the power actually consumed by an AC circuit.
-AVERAGE/ACTIVE/REAL/TRUE POWER
the power taken by a reactance (inductive or capacitive) in an AC circuit.
-REACTIVE/WATTLESS POWER
the cosine of an angle between voltage and current in AC circuit.
-POWER FACTOR
current remain in-phase with voltage real and apparent power arc equal purely passive load.
-UNITY PF
current leads voltage by an angle electrical degree capacitive load.
-LEADING PF
current lags voltage by anangle electrical degree inductive load.
-LAGGING PF
there is a phase difference of 90 electrical degree between current and voltage, so no useful work done purely reactive load.
-ZERO PF
there is a phase difference of 90 electrical degree between current and voltage, so no useful work done purely reactive load.
-ZERO PF
purely inductive load. zero leading. purely capacitive load.
-ZERO LAGGING
is the measure of its quality. The more perfect the inductor, the higehr its Q value.
-THE Q OF AN INDUCTOR
the Q of a coil is also known as the
-MERIT OF A COIL
