Question

A lightbulb uses 100 W of power when connected across 120 V. What is the current drawn by the lightbulb?

A) 12 A
B) 1.0 A
C) 2.0 A
D) 0.8 A

Answer 1

Using the power formula, I = P / V, the current drawn by the 100 W lightbulb connected across 120 V is 0.8333 A. This can be rounded to approximately 0.8 A, making D) 0.8 A the correct answer.

Step-by-step explanation:

The current drawn by the lightbulb can be calculated using the power formula for electric circuits, which is Power (P) = Voltage (V) × Current (I). In this case, the power of the lightbulb is 100 watts (W) and it is connected to a voltage of 120 volts (V).

To find the current (I), we rearrange the power formula to I = P / V. Therefore, the current drawn by the lightbulb is I = 100 W / 120 V = 0.8333 A, which we can round to approximately 0.8 A. Answer D) 0.8 A is the correct choice.

The referenced examples and discussions demonstrate similar situations where voltage, power, and current relationships are analyzed, emphasizing that the provided voltage is an average value due to alternating current (AC) in household power supplies.