What is the principle of rheostat?

A rheostat works on the principle of Ohm’s law. Ohm’s law states that the current in a circuit is inversely proportional to the resistance at the given temperature.


Related Questions

  1. What Is The Formula Of Ammeter?
  2. What is the necessary condition for a conductor to obey Ohm's Law?
  3. Why is the series arrangement not used for domestic circuits?
  4. Define: 1 volt, Potential difference
  5. The resistance R= V/I, where V=100 ± 5.0V and I = 10 ± 0.2A. What is the total error in R?
  6. Draw a circuit diagram to verify ohm’s law.
  7. Is resistance constant in Ohm's law?
  8. What are the applications of ohm's law used in daily life?
  9. State And Explain Joules Law Of Heating.
  10. Why is the curve representing Ohm's law linear?
  11. What are ohmic and non-ohmic devices? Give examples.
  12. Obtain the equation J = σE of Ohm's law on the basis of drift velocity
  13. Find the current through a resistance 2 ohm if the voltage across the resistance is 6 V.
  14. A small bulb has a resistance of 2 ohms when it is cold. It draws 0.4-ampere current from a source of4V and then starts glowing. Calculate the resistance when it is glowing
  15. Why Do We Use Ohm's Law?

Read More:

CBSE CLASS XII Related Questions

  • 1.
    This ‘average velocity’ is found be few mm/s for currents in range of a few amperes. How then is current established almost the instant a circuit is closed ?


      • 2.
        An electric field $\vec{E}$ is established across the ends of a cylindrical conductor of length L and area of cross-section A. Discuss how electrons attain an average velocity, independent of time. Hence, obtain a relation between current in the conductor and this ‘average velocity’ of electrons.


          • 3.
            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.


              • 4.
                Read the following paragraph and answer the questions that follow.
                A p-type or n-type semiconductor can be converted into a p-n junction by doping it with suitable impurity. The motion of majority charge carriers causes diffusion current across the junction while the barrier electric field causes motion of minority carriers for drift current. In case of unbiased diode, the diffusion and drift currents are equal. This equilibrium is disturbed by the biasing batteries. Diodes, therefore, allow currents in one direction. This property of diode is used in making rectifiers.


                  • 5.
                    Write two advantages of reflecting telescope over refracting telescope.


                      • 6.
                        A student sets up the circuit as shown in the figure to find the value of unknown resistance X and records a set of readings of the voltmeter and the ammeter by using the rheostat.

                          CBSE CLASS XII Previous Year Papers

                          Comments


                          No Comments To Show