# Resistor Problem involving Lightbulbs

1. Mar 22, 2015

### ryankunzzz

1. The problem statement, all variables and given/known data
We have 6 lightbulbs that are identical attached to a battery, and we need to list them from brightest to dimmest.

This is what they look like.

2. Relevant equations

None...?

3. The attempt at a solution

So, my thinking is that bulbs 6,1,2 are the brightest and the same, because the same amount of current is flowing through them, then I think that 3 is brighter than 4 and 5 which are equal...

This is wrong and I dont know why.

2. Mar 22, 2015

### Staff: Mentor

I agree with your answer. Why do you think it would be wrong?

3. Mar 22, 2015

### ryankunzzz

I dont know. As long as someone agrees with this, I'll talk to my teacher.

4. Mar 22, 2015

### SammyS

Staff Emeritus
Yes, you are correct.

5. Mar 24, 2015

### abbas_majidi

Hello my friend
Your answer is correct. Brightness of bulbs is proportional power of them.
P=R×I×I
Therefore brightness of bulbs:
6,1,2(are same)>3>4,5(are same)