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32 Cards in this Set
- Front
- Back
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voltage, V |
U/Q (energy per unit charge) |
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Vs |
Vr + Vb |
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Current, I [A] = |
delta Q/ delta t |
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Current, I = |
n.A.Vave.e |
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ohms law |
R = V/I |
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Impedance, Z |
Z = V/I |
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Capacitance, C |
= Q/V |
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Reactance of capacitor, Xc |
= V(t)/C(t) = 1/jwc |
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|reactance of capacitor|, |Xc| |
= 1/wc = 1/2pifC |
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Voltage across inductor, VL |
= L . dI/dt |
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impedance across inductor, ZL |
= XL = jwL |
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Power, P |
= VI = I^2R = V^2/R |
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rms value |
= A/SQRT2 |
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Irms |
= Imax/SQRT2 |
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Vrms |
= Vmax/SQRT2 |
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Prms |
= Vrms . Irms |
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Energy |
= P x t |
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Cost
kWh |
kWh x running time x £ per kWh
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Voltage across potential divider |
V1 = R1/R1+R2 . Vs |
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Current divider rule |
I1 = R1/R1+R2 . Is |
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Linear circuit |
Vout = k Vin |
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Low pass filter - gain |
G = Vout/Vin = Xc/R+Xc |
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Low pass filter - |gain| |
|G| = 1 / SQRT(1 + (wCR)^2) |
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Critical frequency, fc |
fc = 1 / 2.pi.RC |
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High pass filter - Vout, |
Vout = R / R+Xc . Vin |
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High pass filter, gain |
G = |Vout/Vin | = wCR / SQRT( 1 + (wCR)^2 ) |
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Time Constant, tau |
tau = RC |
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98% for time constant |
= 4(tau) |
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Diode equation |
Id = Is ( e^(qV/nkT) -1 ) Is - reverse saturation current k - boltzmann constant T - absolute temperature V - applied voltage across diode n - ideality factor ( n=1=ideal diode) q - charge of electron |
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Kirchoffs Current rule (KCR) |
The total current entering a node in a circuit is equal to the total current leaving that node entering node +ve leaving node -ve |
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Kirchhoffs Voltage rule (KVR) |
The sum of all voltage sources and drops (sinks) around a closed circuit loop |
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Inductance, L |
= N^2 . uo . ur A / l |
