Basic Electrical Engineering
Basic Electrical Formula:
The most common used electrical formulas – Ohms Law and combinations. Common electrical units used in formulas and equations are
Electrical Voltage – Ohm’s Law
Ohm’s law can be expressed as:
V = R I (1a)
V = P / I (1b)
V = (P R)1/2 (1c)
Electric Current – Ohm’s Law
I = V / R (2a)
I = P / V (2b)
I = (P / R)1/2 (2c)
Electric Resistance – Ohm’s Law
R = V/ I (3a)
R = V2/ P (3b)
R = P / I2 (3c)
Electric Power
P = V I (4a)
P = R I2 (4b)
P = V2/ R (4c)
where
P = power (watts, W, J/s)
V = voltage (volts, V)
I = current (amperes, A)
R = resistance (ohms, Ω)
Electric Energy
Electric energy is power multiplied with time:
W = P t (5)
where
W = energy (Ws, J)
t = time (s)
Alternative – power can be expressed
P = W / t (5b)
Power is consumption of energy by consumption of time.