 #1
np115
 5
 3
 Homework Statement:

What is the emf of the battery in the figure(Figure 1)?
What is the internal resistance of the battery in the figure?
 Relevant Equations:

V=iR
V=Eir
I know the answers are 9 V and .5 ohms but I have no idea how to get there. Originally I solved for Delta V in the open circuit through (1.636)(5) which gave me 8.18V. Then, I solved for Delta V in the closed circuit through (1.565)(1/((1/5)+(1/10)) which gave me 5.51 V. I used these voltages to set up the equations using V=Eir. *this is something that really confuses me! is this equation referring to the total resistance in the circuit or just the internal resistance in the battery? If it is total, how would I put this into the equation?* Using that equation I got 8.18 V = E (1.636 (r+5)) and 5.21 = E  (1.565(r+3.33)). Then, I used elimination to solve but got really confused because things do not add up. I have a quiz tomorrow over this and I have NO IDEA WHAT I"M DOING! Really appreciate some help!