You have a nightlight plugged into an outlet in the hallway, which uses 3.5 watts when plugged in. If the house circuit provides 120.0 volts, what is the current through this bulb?

This problem can be solved by manipulating the formula for power, which is: P = VI. Where:

P = Power in watts

V = Voltage in volts

I = Current in amperes

Since we are already given the power and voltage, simple substitution can be done.

P = VI

3.5 watts = 120 volts * I

I = 3.5 / 120

I = 0.0292 Amperes or 29.2 milliAmperes

Therefore, the current through the bulb is 29.2mA