Resonant Frequency Calculator — calculate resonant frequency with the correct physics formula. Worked example and unit notes included.
V = I × R (Voltage = Current × Resistance)
I = V ÷ R (Current = Voltage ÷ Resistance)
R = V ÷ I (Resistance = Voltage ÷ Current)
P = V × I = I² × R = V² ÷ R (Power in watts)
Worked example: a 12V car battery connected across a 4Ω resistor: I = 12 ÷ 4 = 3A. Power dissipated = 12 × 3 = 36W. The resistor must be rated at least 36W to avoid burning out. For household wiring: a 240V circuit with a 13A fuse has a maximum safe power load of 240 × 13 = 3,120W — enough for a kettle (2,400W) but not two kettles simultaneously.