Use the exact values you enter in previous answer(s) to make later calculations.

Question

Use the exact values you enter in previous answer(s) to make later calculations. The battery in the figure below is a real battery. That is, it has some internal resistance R_int in series with an ideal battery with an emf of V_0. In an attempt to determine R_int and V_0, a resistor R_1 = 720 ohm is first placed across points A and B, and the voltage across the resistor is measured to be 5.0 V. This resistor is then replaced with a second resistor with R_2 = 2,900 ohm, and the voltage across R_2 is found to be 9.8 V. Find R_int and V_0.

Explanation / Answer

Emf of Battery, = Vo
Internal Resistance, = Rint

Now equations are as follow,
Current across R1, I1 = 5.0/720 A

Vo = I1*(R1 + Rint)
Vo = (5.0/720) * (720 + Rint) --------1

Current across R2 , I2 = 9.8/2900 A
Vo = I2*(R2 + Rint)
Vo = (9.8/2900) * (2900 + Rint) --------2

Solving eq 1 & 2 ,
Vo = 13.25 V
Rint = 1346 ohm

Related Questions

Navigate

• Browse (All)
• Browse U
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.