In the given potentiometer circuit arrangement, the balancing length ${AC}$ is measured to be $250$ ${cm}$. When the galvanometer connection is shifted from point $(1)$ to point $(2)$ in the given diagram, the balancing length becomes $400\, {cm}$. The ratio of the emf of two cells, $\frac{\varepsilon_{1}}{\varepsilon_{2}}$ is -
JEE MAIN 2021, Diffcult
Download our app for free and get startedPlay store
$E_{1}=k l_{1} \ldots .$ (i)

$E_{1}+E_{2}=k l_{2} \ldots$ (ii)

$\frac{E_{1}}{E_{1}+E_{2}}=\frac{l_{1}}{l_{2}}=\frac{250}{400}=\frac{5}{8}$

$8 E_{1}=5 E_{1}+5 E_{2}$

$3 E_{1}=5 E_{2}$

$\frac{E_{1}}{E_{2}}=\frac{5}{3}$

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
    $A \,6 \,V$ battery of negligible internal resistance is connected across a uniform wire of length $1\, m$. The positive terminal of another battery of emf $4\,V$ and internal resistance $1\, \Omega$ is joined to the point $A$ as shown in figure. The ammeter shows zero deflection when the jockey touches the wire at the point $C$. The $AC$ is equal to
    View Solution
  • 2
    A galvanometer of resistance, $G,$ is connected in a circuit. Now a resistance $R$ is connected in series of galvanometer. To keep the main current in the circuit unchanged, the resistance to be put in parallel with the series combination of $G$ and $R$ is
    View Solution
  • 3
    Three resistances $4\,\Omega $ each of are connected in the form of an equilateral triangle. The effective resistance between two corners is
    View Solution
  • 4
    The reading of the ammeter as shown in figure
    View Solution
  • 5
    Two electric lamps of $40\, watt$ each are connected in parallel. The power consumed by the combination will be ........... $watt$
    View Solution
  • 6
    Infinite number of cells having $emf$ and internal resistance $\left( {E,r} \right)$, $\left( {\frac{E}{n},\frac{r}{n}} \right)$, $\left( {\frac{E}{{{n^2}}},\frac{r}{{{n^2}}}} \right)$, $\left( {\frac{E}{{{n^3}}},\frac{r}{{{n^3}}}} \right)$..... are connected in series in same manner across an external resistance of $\frac{{nr}}{{n + 1}}$ . Current flowing through the external resistor is
    View Solution
  • 7
    The following four wires are made of the same material and are at the same temperature. Which one of them has highest electrical resistance
    View Solution
  • 8
    A circuit of resistacne $R$ is connected to $n$ similar cells. If the current in the circuit is the same when the cells are connected in series or in parallel. If the internal resistacne $r$ of each cell then
    View Solution
  • 9
    A $5\, V$ battery with internal resistance $2\, \Omega$ and a $2\,V$ battery internal resistance  $1\, \Omega$ are connected to a $10\, \Omega$ resistor as shown in the figure. The current in the $10\, \Omega$ resistor is :-
    View Solution
  • 10
    Of the two bulbs in a house hold circuit, one glows brighter than the other, Which of the two bulbs has a large resistance?
    View Solution