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

Question:

The length of a wire of a potentiometer is $100 \mathrm{~cm}$, and the e. m.f. of its standard cell is $\mathrm{E}$ 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 $\ell=30 \mathrm{~cm}$ from the positive end, the e.m.f. of the battery is

  1. $\frac{30 E}{100.5}$

  2. $\frac{30 E}{(100-0.5)}$

  3. $\frac{30(E-0.5 i)}{100}$

  4. $\frac{30 E}{100}$


Correct Option: 4

JEE Main Previous Year 1 Question of JEE Main from Physics Current Electricity chapter.
JEE Main Previous Year 2003

Solution:

Related Questions

  • A circuit to verify Ohm’s law uses ammeter and voltmeter in series or parallel connected correctly to the resistor. In the circuit:

    View Solution

  • Consider four conducting materials copper, tungsten, mercury and aluminium with resistivity $\rho_{C}, \rho_{T}, \rho_{M}$ and $\rho_{A}$ respectively. Then :

    View Solution

  • To verify Ohm’s law, a student connects the voltmeter across the battery as, shown in the figure. The measured voltage is plotted as a function of the current, and the following graph is obtained :

    If $\mathrm{V}_{\mathrm{o}}$ is almost zero, identify the correct statement:

    View Solution

  • A current of $5 \mathrm{~A}$ passes through a copper conductor (resistivity) $=1.7 \times 10^{-8} \Omega \mathrm{m}$ ) of radius of cross-section $5 \mathrm{~mm}$. Find the mobility of the charges if their drift velocity is $1.1 \times 10^{-3} \mathrm{~m} / \mathrm{s}$.

    View Solution

  • In an experiment, the resistance of a material is plotted as a function of temperature (in some range). As shown in the figure, it is a straight line.

    One may canclude that:

    View Solution

  • Space between two concentric conducting spheres of radii $a$ and $b(b>a)$ is filled with a medium of resistivity $\rho$. The resistance between the two spheres will be :

    View Solution

  • In a conductor, if the number of conduction electrons per unit volume is $8.5 \times 10^{28} \mathrm{~m}^{-3}$ and mean free time is $25 f s$ (femto second), it’s approximate resistivity is $\left(\mathrm{m}_{0}=9.1 \times 10^{-31} \mathrm{~kg}\right)$

    View Solution

  • A $200 \Omega$ resistor has a certain color code. If one replaces the red color by green in the code, the new resistance will be :

    View Solution

  • The charge on a capacitor plate in a circuit, as a function of time, is shown in the figure:

    What is the value of current at $\mathrm{t}=4 \mathrm{~s}$ ?

    View Solution

  • A resistance is shown in the figure. Its value and tolerance are given respectively by:

    View Solution

Leave a Reply

Your email address will not be published.

error: Content is protected !!
Download App