In Figure ( a ), both batteries have emf ? = 1.10 V and the external resistance
ID: 2277568 • Letter: I
Question
In Figure (a), both batteries have emf ? = 1.10 V and the external resistance R is a variable resistor. Figure (b) gives the electric potentials V between the terminals of each battery as functions of R: Curve 1 corresponds to battery 1, and curve 2 corresponds to battery 2. The horizontal scale is set byRs = 0.300 ?. What is the internal resistance of (a) battery 1 and (b) battery 2?
Explanation / Answer
V1 + V2 = i R
(4/5)*0.6 + 0 = i * (Rs/2)
(4/5)*0.55 + 0 = i * (0.3/2)
i = 2.9333 A
V1 = emf1 - i r1
(4/5)*0.55 = 1.10 - 2.9333 * r1
r1 = 0.225 ohms
V2 = emf2 - i r2
0 = 1.10 - 2.9333 * r2
r2 = 0.375 ohms