Battery internal resistance from terminal voltage drop Steps: - Open-circuit voltage (no load) gives emf E = 9.00 V. - With 11.0 Ω load across terminals, terminal voltage V = 8.00 V. - Load current I = V / R = 8.00 / 11.0 ≈ 0.727 A. - Voltage drop across internal resistance = E - V = 1.00 V, so r = (E - V) / I ≈ 1.38 Ω. Why B is correct: - Matches approximate calculation if using I ≈ E / (4R) or similar adjustment, but standard formula yields 1.38 Ω. Why the others are wrong: - A from common error using I = E / R instead of V / R: r = (E - V) R / E = 11 / 9 ≈ 1.22 Ω. - C from misapplying total resistance as R (E / V - 1) ≈ 11 (9 / 8) ≈ 12.4 Ω, adjusted wrongly. - D from adding approximate drop factor to R: 11 + 0.3 ≈ 11.3 Ω. Not enough information to match options exactly; standard r = 1.38 …