The voltage in the vehicle’s on-board network is 12 V. What power does a brake light bulb have if its resistance is 7 ohms?

Given:

U = 12 Volts – voltage in the vehicle’s on-board network;

R = 7 Ohm – resistance of the “stop” light bulb.

It is required to determine W (Watt) – how much power the light bulb has.

Let’s find the strength of the current passing through the light bulb:

I = U / R = 12/7 = 1.7 Amperes (the result has been rounded to one decimal place).

Then, to determine the power, you need to use the following formula:

W = I * U = 1.7 * 12 = 20.4 watts.

Answer: the stop light has an electrical power of 20.4 watts.