Answer to Question #88966 in Molecular Physics | Thermodynamics for gc

Question

The resistance of each brake lightbulb on an automobile is
4.0 Ω.
Use the fact that cars have 12-V electrical systems to compute the current that flows in each bulb if they are connected in series. (For simplicity, assume that the circuit is only composed of one brake lightbulb and the car battery.)

Answer 1

Assuming the simplest case that a circuit is only composed of one brake lightbulb and the car battery (as it is stated in the question), one can apply the Ohm's law to calculate the current in the circuit:

$$I = \frac{U}{R},$$

where U is the voltage of the battery any R is the resistance of the bulb.

Substituting the numerical values, we obtain:

$$I = \frac{12}{4} = 3 \,A$$

Answer: 3 A.