Under what conditions current passing through a resistance $R$ can be increased by short circuiting the battery of emf $E_2$. The internal resistances of the two batteries are $r_1$ and $r_2$ respectively
Medium
Download our app for free and get startedPlay store
The current through the circuit before the battery of $\mathrm{emf}$ $\mathrm{E}_{2}$ is short circuited is,

$I_{1}=\frac{E_{1}+E_{2}}{R+r_{1}+r_{2}}$

After short circuiting the battery of $\mathrm{emf}$ $\mathrm{E}_{2}$. current through resistance $\mathrm{R}$ would be,

$I_{2}=\frac{E_{1}}{R+r_{1}}$

Now, $\quad \mathrm{I}_{2}>\mathrm{I}_{1}$

$\therefore $ ${\frac{\mathrm{E}_{1}}{\mathrm{R}+\mathrm{r}_{1}}>\frac{\mathrm{E}_{1}+\mathrm{E}_{2}}{\mathrm{R}+\mathrm{r}_{1}+\mathrm{r}_{2}}} $

${\mathrm{E}_{1} \mathrm{r}_{2}>\mathrm{E}_{2}\left(\mathrm{R}+\mathrm{r}_{1}\right)}$

art

Download our app
and 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

  • 1
    Two wires that are made up of two different materials whose specific resistance are in the ratio $2 : 3$, length $3 : 4$ and area $4 : 5$. The ratio of their resistances is
    View Solution
  • 2
    Assertion : An electric bulb becomes dim, when the electric heater in parallel circuit is switched on.

    Reason : Dimness decreases after sometime.

    View Solution
  • 3
    Potential difference across the terminals of the battery shown in figure is .................... $V$ ($r =$ internal resistance of battery)
    View Solution
  • 4
    Two batteries of $e.m.f.$ $4\,V$ and $8 \,V$ with internal resistances $1\, \Omega$ and $2\,\Omega$ are connected in a circuit with a resistance of $9 \,\Omega$ as shown in figure. The current and potential difference between the points $P$ and $Q$ are
    View Solution
  • 5
    The two bulbs as in the above question are connected in series to a $200\, volt$ line. Then
    View Solution
  • 6
    $A$ brass disc and a carbon disc of same radius are assembled alternatively to make a cylindrical conductor. The resistance of the cylinder is independent of the temperature. The ratio of thickness of the brass disc to that of the carbon disc is [$\alpha$ is temperature coefficient of resistance and Neglect linear expansion ]
    View Solution
  • 7
    A $16\, \Omega$ wire is bend to form a square loop. A $9 \,{V}$ supply having internal resistance of $1 \,\Omega$ is connected across one of its sides. The potential drop across the diagonals of the square loop is $.......\,\times 10^{-1} \,{V}$
    View Solution
  • 8
    The colour sequence in a carbon resistor is red, brown, orange and silver. The resistance of the resistor is
    View Solution
  • 9
    A $2\, W$ carbon resistor is color coded with green, black, red and brown respectively. The maximum current which can be passed through this resistor is .............. $mA$
    View Solution
  • 10
    What is the reading of voltmeter in the following figure .............. $V$
    View Solution