Phasors + J-Notation + RC Circuits Flashcards
How to you calculate angular frequency of a sine wave
2pifrequency
1/ Time period = frequency
Derive the voltage function of a sinusoidal supply
Peak voltage * sin(ωt) where ω = angular frequency
Derive the current function of a sinusoidal supply applied to a capacitor
Describe a phase shift
where a waveform is delayed or advanced in time relative to another waveform
measured in radians
If a sinusoidal voltage supply is connected to a resistor, describe the relationship between the voltage function and the current function
voltage across terminals and current function are in phase
If a sinusoidal voltage supply is connected to a capacitor, describe the relationship between the voltage function and the current function
Current function through capacitor branch leads the voltage function by Pi radians
How do you calculate capacitive reactance from the current and voltage functions
using euler’s law , show the derivation for the general formula to calculate capactive reactance
Explain how a phasor is mapped from a sine wave
A full rotation of a phasor is a full cycle of the waveform
The length of the vector represents the peak magnitude
X axis = time , y axis = magnitude at time t
hence vertical component is the function
How do you superimpose two waves in phasor notation
Construct a parallelogram using each vector as a side of the parallelogram
origin to the opposing corner length is the magnitude of the superimposed wave.
and that vector itself represents the superimposed wave
Explain what a High Pass Filter does and Draw a circuit for one.
Attenuate Lower frequencies, but allow Higher ones
Explain what a Low Pass Filter does and Draw a circuit for one.
Attenuate Higher frequencies, but allow Lower ones
What is a Frequency response or a gain curve
Plot of Magnitude response( gain) against frequency
How do you calculate the Magnitude Response
Convert Gain into the decibel scale using Power and Voltage Inputs and outputs
how can write Vout/Vin in terms of Angular Frequency Resistance and Capacitance in a high pass circuit
Whats the Equation for the magnitude response of a high pass circuit
Whats the Equation for the phase response of a high pass circuit
whats the voltage and frequency of UK socket voltage and frequency
240V , 50Hz
What is the equation for RMS Voltage
V0/root2
0.707xV0
What is the significance of RMS
any power calculated from an AC source has to be calculated using RMS voltage and RMS current
p=VRMS * IRMS , VRMS^2 / Z , IRMS^2 *Z
Derive a mathematical explanation as to why if you match the theverin voltage to the voltage of the load, maximum power is dissipated.
