The internal resistance of a cell depends on

Two batteries with different $emf$ and different internal resistances are connected as shown in the figure. The voltage between the two terminals $A$ and $B$ is ........ $volt$.

$A$ storage battery is connected to a charger for charging with a voltage of $12.5 \text{ V}$. The internal resistance of the storage battery is $1 \ \Omega$. When the charging current is $0.5 \text{ A}$,the $EMF$ of the storage battery is: ............... $\text{volts}$

Each of the six ideal batteries of emf $20 \, V$ is connected to an external resistance of $4 \, \Omega$ as shown in the figure. The current through the resistance is (in $ \, A$)

$EMF$ is most closely related to

$A$ battery of $24$ cells,each of emf $1.5\, V$ and internal resistance $2\, \Omega$,is to be connected to send the maximum current through a $12\, \Omega$ resistor. The correct arrangement of cells will be: