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?

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CBSE CLASS XII Related Questions

  • 1.
    A long solenoid of length \( L \) and radius \( r_1 \) having \( N_1 \) turns is surrounded symmetrically by a coil of radius \( r_2 \, (r_2>r_1) \) having \( N_2 \) turns (\( N_2 \ll N_1 \)) around its mid-point. Derive an expression for the mutual inductance of solenoid and coil. Is \( M_{12} = M_{21} \) valid in this case?


      • 2.
        Two small identical metallic balls having charges \( q \) and \( -2q \) are kept far at a separation \( r \). They are brought in contact and then separated at distance \( \frac{r}{2} \). Compared to the initial force \( F \), they will now:

          • attract with a force \( \frac{F}{2} \)
          • repel with a force \( \frac{F}{2} \)
          • repel with a force \( F \)
          • attract with a force \( F \)

        • 3.
          A tank is filled with a liquid to a height of \( 12.5 \, \text{m} \). The apparent depth of a needle lying at the bottom of the tank is measured to be \( 9.0 \, \text{m} \). Calculate the speed of light in the liquid.


            • 4.
              Draw a circuit diagram of a full-wave rectifier using p-n junction diodes. Explain its working and show the input-output waveforms.


                • 5.
                  Draw the number of scattered particles versus the scattering angle graph for scattering of alpha particles by a thin foil. Write two important conclusions that can be drawn from this plot.


                    • 6.
                      Photoemission of electrons occurs from a metal (\( \phi_0 = 1.96 \, \text{eV} \)) when light of frequency \( 6.4 \times 10^{14} \, \text{Hz} \) is incident on it. Calculate: Energy of a photon in the incident light, The maximum kinetic energy of the emitted electrons, and The stopping potential.

                        CBSE CLASS XII Previous Year Papers

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