A cell of emf 2V and internal resistance 0.1 Ω is connected to a 3.9 Ω external resistance. What will be the potential difference across the terminals of the cell ?
Open in App
Solution
Internal resistance of the battery and the external resistance are connected in series.
R = 3.9 + 0.1 = 4.0 ohm
Current in the circuit = E/R = 2/4 = 0.5 A
terminal voltage of the battery = E - Ir
= 2 - 0.5*0.1 = 1.95 volt.