Practical Electronics/Basic Theory/General Formulae

Charge

Charge refers to quantities of Electric Charge of an object

1 C = Number of Electrons e

Voltage is defined as Work done on a Charge

Q=\int Wdt

Current is defined as ratio of Charge over Time

I={\frac {Q}{t}}

I , Current

Q , Charge

t , Time

1A={\frac {1C}{1s}}

R={\frac {V}{I}}

R , Resistance

V , Voltage

I , Current

G={\frac {1}{R}}

G={\frac {I}{V}}

G , Conductance

R , Resistance

I , Current

V , Volatge

X = ± j ω T

X , Reactance

ω , Angular of Frequency

T , Time Constant

Z = R + X

Z , Impedance

R , Resistance

X , Reactance

P _R = I V =

I^{2}R

=

{\frac {V^{2}}{R}}

P=P_{V}-P_{R}=VI-I^{2}R=VI-{\frac {V^{2}}{R}}

P_{C}={\frac {1}{2}}CV^{2}

P_{L}={\frac {1}{2}}LI^{2}