# 1.5V/3W lightbulbs with a 9V battery. Will they burn out?

**1. The problem statement, all variables and given/known data**

Imagine that you have a box of 9V batteries and a box of flashlight bulbs labeled 1.5V/3W for operational voltage/power. What is the ohmic resistance of the bulbs? Can you turn on the 1.5V bulbs without burning them out by using the available 9V batteries?

**2. Relevant equations**

P=ΔW/t=ΔVI=ΔV^{2}/R=I^{2}R

I = P/V

R = V/I

**3. The attempt at a solution**

I in the bulbs will be 3W/1.5V which is 2A

R in the bulbs will be 1.5V/2A which is .75ohms

If you attach one of the bulbs to a 9V battery, the voltage drop will be = to IR which is (2A)(.75ohms) which is 1.5V. So using a 9V battery the bulb will only get 1.5V which will not cause the bulb to burn out. Is this correct?

**1. The problem statement, all variables and given/known data**

**2. Relevant equations**

**3. The attempt at a solution**

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