Download App
The length of a wire of a potentiometer is $100\, cm$, and the $emf$ of its standard cell is $E\,volt$. It is employed to measure the $e.m.f$ of a battery whose internal resistance is $0.5 \,\Omega$. If the balance point is obtained at $l = 30\, cm$ from the positive end, the $e.m.f.$ of the battery is

where $i$ is the current in the potentiometer

  • A$\frac{{30E}}{{100}}$
  • B$\frac{{30E}}{{100.5}}$
  • C$\frac{{30E}}{{(100 - 0.5)}}$
  • D$\frac{{30(E - 0.5i)}}{{100}}$, 
AIEEE 2003, Medium
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.*
Download App

Similar Questions

  • 1
    In the figure given below, the current passing through $6\,\Omega $ resistor is ........... $ampere$
    View Solution
  • 2
    The potential difference across $8\, ohm$ resistance is $48\, volt$ as shown in the figure. The value of potential difference across $X$ and $Y$ points will be ............. $volt$
    View Solution
  • 3
    In the adjoining circuit diagram each resistance is of $10$ $\Omega$. The current in the arm $AD$ will be
    View Solution
  • 4
    A potentiometer wire of length $300\,cm$ is connected in series with a resistance $780\,\Omega$ and a standard cell of emf $4\,V$. A constant current flows through potentiometer wire. The length of the null point for cell of emf $20\,mV$ is found to be $60\,cm$. The resistance of the potentiometer wire is$...\Omega$
    View Solution
  • 5
    In the circuit shown the readings of ammeter and voltmeter are $4\,\, A$ and $20\,\, V$ respectively. The meters are non ideal, then $R$ is
    View Solution
  • 6
    Consider the circuit shown in the figure. The current ${I_3}$ is equal to
    View Solution
  • 7
    Resistance of one carbon filament and one tungsten lamp are measured individually when the lamp are lit and compared with their respective resistances when cold. Which one of the following statements will be true
    View Solution
  • 8
    A current of $1.6\, A$ is flowing through a wire having cross-sectional area $1\, mm^2$. If density of free electrons in the material of the wire is $10^{29}\, per\, m^3$, the drift velocity of electrons will be
    View Solution
  • 9
    A potential difference is applied across the ends of a metallic wire. If the potential difference is doubled, then the drift velocity
    View Solution
  • 10
    During lighting, a current pulse, shown in figure, flows from the cloud at a height $1.5\ km$ to the ground. If the breakdown electric field of humid air is about $400\ kVm^{-1}$ , the energy released during lighting would be (in unit of $10^9\ J$ )
    View Solution