A small radio operates on 4.11 V and has a resistance of 22.68 Ω. At what rate does this radio use electric energy?

Question

show units: type V for Volts, A for amps, ohms for Ω , W for Watts, eV for electron volts, Hz for Hertz, N for newtons,  m for meters, s for seconds, J for Joules, W for Watts, m/s for meters per second  etc.

Answer 1

P = rate of electrical energy use in watts

P = V^2 / R

V = 4.11 volts

R = 22.68 ohms

Plug in the numbers and get P in watts.