If in the previous problem the battery is being charged with a current of 5 amp, in what direction will current flow inside the battery, and what will be the reading of the voltmeter

Explanation

In charging a battery, positive terminal of the battery is connected to positive terminal of the charger. Hence, the current inside the battery is from anode to cathode. The net change in potential energy for a charge q making a round trip around a complete circuit must be zero. Hence, the net change in potential around the circuit must also be zero. In other words, the algebraic sum of potential difference and emf.s around the loop is zero. Considering the section ab
`V_(a) - Ir + E = V_(b)`
or `V_(a)-V_(a) = V_(ab)= E + Ir`
or, `V_(ab) = 12 + 5 xx 2 = 22` volt`
Note: If the terminals of the battery are connected directly to each other with no external resistance, then situation is called a short circuiting of battery