Question

The power in a lightbulb is given by the equation P = RI², where R is the resistance of the lightbulb. What is the current in a circuit that has a resistance of 25.0 and a power of 30.0 W?

A) 0.910 A
B) 1.20 A
C) 0.830 A
D) 1.09 A

Answer 1

To find the current in a lightbulb circuit with a resistance of 25.0 ohms and a power of 30.0 watts, you use the formula P = RI² and solve for I, resulting in 1.09 A.

Step-by-step explanation:

The power P in a lightbulb is related to the resistance R and the square of the current I as per the equation P = RI². To find the current in a circuit with a resistance of 25.0 ohms and a power of 30.0 watts, we rearrange the equation to solve for I, which results in I = √(P/R). Plugging in the given values yields I = √(30.0 W / 25.0 Ω) which calculates to 1.095 A. Therefore, the value closest to our result from the given options is D) 1.09 A.