In a potentiometer experiment two cells of $e.m.f.$ $E_1$ and $E_2$ are used in series and in conjunction and the balancing length is found to be $58\, cm$ of the wire. If the polarity of $E_2$ is reversed, then the balancing length becomes $29\, cm$. The ratio $\frac{{{E_1}}}{{{E_2}}}$ of the $e.m.f.$ of the two cells is
Medium
Download our app for free and get startedPlay store
(c) $\frac{{{E_1}}}{{{E_2}}} = \frac{{{l_1} + {l_2}}}{{{l_1} - {l_2}}} = \frac{{58 + 29}}{{58 - 29}} = \frac{3}{1}$
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
    Ohm's law fails in
    View Solution
  • 2
    A wire has resistance $12\,\Omega $. It is bent in the form of a circle. The effective resistance between the two points on any diameter is equal to ................ $\Omega$
    View Solution
  • 3
    The resistance of $10\, metre$ long potentiometer wire is $1\,ohm/meter$. A cell of $e.m.f.$ $2.2\, volts$ and a high resistance box are connected in series to this wire. The value of resistance taken from resistance box for getting potential gradient of $2.2\, millivolt/metre$ will be ............... $\Omega $
    View Solution
  • 4
    The current $i_1$ and $i_2$ through the resistor $R_1 (= 10\,\Omega )$ and $R_2 (=30 \,\Omega )$ in the circuit diagram with $E_1 = 3\,V, E_2 = 3\,V$ and $E_3 = 2\,V$ are respectively:
    View Solution
  • 5
    Read the following statements carefully :

    $Y :$ 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 :

    View Solution
  • 6
    In the given circuit, calculate the value of current in $4.5\,\Omega $ resistor .............. $\mathrm{A}$
    View Solution
  • 7
    If each resistance in the figure is of $9\,\Omega$ then reading of ammeter is ............ $A$
    View Solution
  • 8
    Three $60\, W$ light bulbs are mistakenly wired in series and connected to a $120\,V$ power supply. Assume the light bulbs are rated for single connection to $120\,V$. With the mistaken connection, the power dissipated by each bulb is: .................. $W$
    View Solution
  • 9
    The resistivity of alloys $ = {R_{{\rm{alloy}}}}$; the resistivity of constituent metals ${R_{{\rm{metal}}}}$. Then, usually
    View Solution
  • 10
    Which device can convert all electrical energy into heat
    View Solution