Combination of Cells in Series and Parallel

Two cells of emf  $E_1$  and  $E_2$  and internal resistance  $r_1$  and  $r_2$ , are connected in parallel with each other. Obtain expressions for the equivalent emf and equivalent internal resistance of this parallel combination.

The combination of two identical cells, whether connected in series or parallel combination provides the same current through an external resistance of $2 \mathrm{\Omega }$. The value of internal resistance of each cell is

To draw a maximum current from a combination of cells, how should the cells be grouped?

A student connects four cells, each of emf $1.5 \mathrm{V}$ and internal resistance$0.25 \mathrm{\Omega }$ in series but one cell has its terminals reversed. This battery sends current in a $2 \mathrm{\Omega }$ resistor. The current is :

To get maximum current through a resistance of $2.5\mathrm{\Omega }$, one can use $m$ rows of cells, each row having $n$ cells. The internal resistance of each cell is $0.5\mathrm{\Omega }$. What are the values of $n \& m$, if the total number of cells is $45$?

Reading of Ammeter  and  will be respectively :-

Two cells with the same emf $\epsilon$ and internal resistance $r_{1 }\& r_2$ are connected in series to an external resistance $R\mathit{.}$ The value of $R$ so that the potential difference across the first cell be zero is:

The potential difference between points $A$ and $B$ is-

Two cells having the internal resistance $0.2 \mathrm{\Omega }$ and $0.4 \mathrm{\Omega }$ are connected in parallel. The voltage across the battery terminal is $1.5 \mathrm{V}$. The emf of first cell is $1.2 \mathrm{V}$. The emf of second cell is

Two batteries of emf $E_1$ and $E_2\left(E_2>E_1\right)$ and internal resistances $r_1$ and $r_2$, respectively are connected in parallel as shown in the figure. Which of the following options is correct?

Two batteries of emf $E_1$ and $E_2$ $\left(E_2>E_1\right)$ and internal resistances $r_1$ and $r_2$ respectively are connected in parallel as shown in the figure. Then, which of the following statements is correct?

In the given network of ideal cells and resistors, ${\mathrm{R}}_1=1.0 \mathrm{\Omega }$, ${\mathrm{R}}_2=2.0 \mathrm{\Omega }$, ${\mathrm{E}}_1=2 \mathrm{V}$ and ${\mathrm{E}}_2={\mathrm{E}}_3=4 \mathrm{V}$. The potential difference between the point $\mathrm{a}$ and $\mathrm{b}$ is 

The potential difference between the points $\mathrm{A}$ and $\mathrm{B}$ in the given circuit is

Each of the six ideal batteries of emf $20 V$ is connected to an external resistance of $4 \mathrm{\Omega }$ as shown in the figure. The current through the resistance is

In the arrangement shown in figure, the current through $5\mathrm{\Omega }$ resistor is

A rheostat is used in an electrical circuit

A battery of the emf $18 \mathrm{V}$ and internal resistance of $3 \mathrm{\Omega }$ and another battery of emf $10 \mathrm{V}$ and internal resistance of $1 \mathrm{\Omega }$ are connected as shown in figure. Then the voltmeter reading is

${\mathrm{V}}_{\mathrm{A}}-{\mathrm{V}}_{\mathrm{B}}$ is

Assertion: In series combination of electrical bulbs of lower power emits more light than that of higher power bulb.

Reason: The lower power bulb in series gets more current than the higher power bulb.

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

Reason: Because the effective internal resistance of the cells decreases.