Why Potentiometer Is Preferred Over Voltmeter?

A potentiometer is preferred over a voltmeter when the EMF of the cell is to be measured as the potentiometer does not draw any current because it is a null device.

Voltmeter, on the other hand, draws current from the cell. Therefore, a potentiometer is preferred over a voltmeter to get the actual measurement of EMF.


Related Questions

  1. What is balance point in potentiometer?
  2. What are the types of potentiometers?
  3. Copper is not used as potentiometer wire because?
  4. Which Metal Is Used In Potentiometer?
  5. How does a potentiometer measure EMF?
  6. Sensitivity of potentiometer can be increased by__________.
  7. What is a DC Potentiometer?
  8. Why High Resistance Is Used In Potentiometer?
  9. State the Working Principle of a Potentiometer.
  10. How is potential gradient measured?
  11. What are the advantages of a potentiometer?
  12. What is a null point in a potentiometer?

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CBSE CLASS XII Related Questions

  • 1.
    An astronomical telescope consists of two converging lenses. One of them of large aperture and large focal length is called objective lens and the other one, of smaller focal length and smaller aperture is called the eyepiece. It is used to see distant objects which are not seen clearly with naked eyes. The image formed by the objective lens acts as an object for the eyepiece and the final image produced by the eyepiece is magnified.


      • 2.
        Write two advantages of reflecting telescope over refracting telescope.


          • 3.
            A charged particle $+q$ in an electric field $\vec{E}$ experiences a force in the direction of the electric field. As a result, its kinetic energy changes. Similarly, the charged particle also experiences a force when it moves in a magnetic field $\vec{B}$. But this magnetic force is perpendicular to both velocity $\vec{v}$ of the charged particle and the magnetic field $\vec{B}$, so it cannot change the kinetic energy of the charged particle. Consider two charged particles 1 and 2 of masses $m$ and $\frac{m}{2}$ having charges $-q$ and $+2q$ respectively. They are accelerated from rest through the same potential difference $V$ and acquire kinetic energy $K_1$ and $K_2$. Then they enter in a region of uniform magnetic field $\vec{B}$ perpendicular to their velocities.


              • 4.
                Two metal spheres of radii $r_1$ and $r_2$ ($> r_1$) having charges $q_1$ and $q_2$ respectively kept in air, are brought in contact. Which of the following statements is not correct ?

                  • The total charge of the two spheres is conserved.
                  • Both spheres attain the same potential.
                  • The final potential of the system equals $\frac{1}{4\pi\epsilon_0} \frac{(q_1 + q_2)}{(r_1 + r_2)}$
                  • The final potential of the system equals $\frac{1}{4\pi\epsilon_0} \frac{(q_1 + q_2) (r_1 + r_2)}{r_1 r_2}$

                • 5.
                  Two air-filled capacitors of capacitances $C_1$ and $C_2$ are connected in parallel with a dc battery. After the capacitors are fully charged, a slab of dielectric constant K is inserted between the plates of each capacitor. How will the (i) charge on each capacitor and (ii) energy stored in the capacitor affected after the slab is introduced.


                    • 6.
                      Read the following paragraph and answer the questions that follow.
                      In an experiment with convex lens of focal length f, the screen is fixed at a distance D from the object. A student slowly moves the lens away from the object towards the screen and finds that she is able to form sharp image of the object for two positions of the lens. The distance between these two positions of the lens is d.

                        CBSE CLASS XII Previous Year Papers

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