In the previous problem,if the cells had been connected in parallel (instead of in series),which of the above graphs would have shown the relationship between total current $I$ and $n$ (number of cells)?

When cells are connected in parallel,then

Eels are able to generate current with biological cells called electroplaques. The electroplaques in an eel are arranged in $100$ rows,each row stretching horizontally along the body of the fish containing $5000$ electroplaques. The arrangement is shown below. Each electroplaque has an emf of $0.15\, V$ and internal resistance of $0.25\,\Omega$. The water surrounding the eel completes a circuit between the head and its tail. If the water surrounding it has a resistance of $500\,\Omega$,the current an eel can produce in water is about .............. $A$.

Two batteries of different emfs and different internal resistances are connected as shown. The voltage across $AB$ in volts is

Two cells of $emfs$ $E_1$ and $E_2$ and internal resistances $r_1$ and $r_2$ are connected in parallel. The $emf$ and internal resistance of the equivalent source is

The terminal potential difference of a cell is greater than its $e.m.f.$ when it is