In the given circuit, an ideal voltmeter connected across the $10 \mathrm{\Omega }$ resistance reads $2\mathrm{ }\mathrm{V}$ . The internal resistance $r$, of each cell is:

$n$ identical cells, each of emf $E$ and internal resistance $r$, are joined in series to form a closed circuit. One of the cell $A$ is joined with reversed polarity. The potential difference across each cell except $A$, is :-

$n$ identical cells, each of emf $E$ and internal resistance $r$, are joined in series to form a closed circuit. One of the cell $A$ is joined with reversed polarity. The potential difference across $A$ is :-

In the circuit shown here, ${\mathrm{E}}_1={\mathrm{E}}_2={\mathrm{E}}_3=2 \mathrm{V}$ and ${\mathrm{R}}_1={\mathrm{R}}_2=4 \mathrm{ohms}.$ The current flowing between points A and B through battery E₂ is :

$n$ identical cells whether joined together in series or in parallel, give the same current, when connected to an external resistance '$R$'. The internal resistance of each cell is :—

A group of N cells each of whose emf varies directly with the internal resistance as per the equation E_N = 1.5 r_N are connected as shown in the figure. The current in the circuit is :-

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 suggestively shown below. Each electroplaques has an emf of 0.15 V and internal resistance of $0.25 \mathrm{\Omega }$. The water surrounding the eel completes a circuit between its head and its tail. If the water surrounding it has a resistance of $500 \mathrm{\Omega }$, the current an eel can produce in water is about :-

Assertion : When identical cells are connected in parallel to an external load, the effective e.m.f. increases.

Reason : All the cells will be sending unequal currents to the external load in the same direction.