$10\, Cells$, each of $emf$ $'E'$ and internal resistance $'r'$, are connected in series to a variable external resistance. Figure shows the variation of terminal potential difference of their combination with the current drawn from the combination.$Emf$ of each cell is ................ $V$
Medium
Download our app for free and get started
$6=10 \mathrm{\,E}-12(10 \mathrm{\,r})$ ..........$(1)$
$0=10 \mathrm{\,E}-14(10 \mathrm{\,r})$ ..........$(2)$
So, $6=10 \mathrm{\,E}-12\left[10 \times \frac{\mathrm{E}}{14}\right]$
$E=\frac{42}{10}=4.2 \mathrm{\,V}$
Download our appand get started for free
Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*
Similar Questions
- 1In the network shown in the figure, each of the resistance is equal to $2\,\Omega $. The resistance between the points $A$ and $B$ is .............. $\Omega$View Solution
- 2A cell of negligible resistance and $e.m.f.$ $2$ $volts$ is connected to series combination of $2$, $3$ and $5\, ohm$. The potential difference in volts between the terminals of $3\, ohm$ resistance will beView Solution
- 3Two resistances ${R_1}$ and ${R_2}$ are made of different materials. The temperature coefficient of the material of ${R_1}$ is $\alpha $ and of the material of ${R_2}$ is $ - \beta $. The resistance of the series combination of ${R_1}$ and ${R_2}$ will not change with temperature, if ${R_1}/{R_2}$ equalsView Solution
- 4View SolutionIn charging a battery of motor-car, the following effect of electric current is used
- 5For what value of unknown resistance $X$, the potential difference between $B$ and $D$ will be zero in the circuit shown in the figure ............... $\Omega$View Solution
- 6Read the following statements carefully :View Solution
$Y :$ The resistivity of a semiconductor decreases with increases of temperature.
$Z :$ In a conducting solid, the rate of collision between free electrons and ions increases with increase of temperature.
Select the correct statement from the following :
- 7In the circuit, wire $1$ is of negligible resistance. Then,View Solution
- 8There are $8$ equal resistances $R$. Two are connected in parallel, such four groups are connected in series, the total resistance of the system will beView Solution
- 9In steady state the potential difference across the capacitor is $10\,\, V.$ Each resistance is of $3\,\Omega $. The cell is ideal. The $emf$ of the cell is .............. $\mathrm{V}$View Solution
- 10Water boils in an electric kettle in $15\,\min$ after switching on. If the length of the heating wire is decreased to $2/3$ of its initial value, then the same amount of water will boil with the same supply voltage in ............. $min$View Solution