Explain the relation between current and drift velocity.

Relation between Current and Drift Velocity

  • The electrons move with an average velocity that is independent of time, although electrons get accelerated.
  • This is because an electron suffers collisions with heavy fixed ions, however, after the collision, it will emerge at the same speed in random directions.
  • This average velocity of electrons is known as the drift velocity.

The relation between current and drift velocity is,

I = neAvd

  • where, n refers to the number of free electrons per unit volume,
  • e is the charge of an electron,
  • A is the planar area located inside the conductor.

Related Questions

  1. Give two examples of drift velocity.
  2. What is the relation between drift velocity and electric field?
  3. Two conducting wires X and Y of the same diameter but different materials are joined in series across a battery. If the number density of electrons in X is twice that in Y, find the ratio of the drift velocity of electrons in the two wires.
  4. What Are Two Kinds Of Electricity?
  5. It is known that the drift velocity of electrons is only a few mm/s for a current of a few amperes. How is it possible that a current is established almost instantaneously when a circuit is closed? For example, a bulb glows as soon as the connection is switched on. Explain.

Read More:

CBSE CLASS XII Related Questions

  • 1.
    Draw a circuit diagram of a full-wave rectifier using p-n junction diodes. Explain its working and show the input-output waveforms.


      • 2.
        If Bohr’s quantization postulate (angular momentum \( = \frac{nh}{2\pi} \)) is a basic law of nature, it should be equally valid for the case of planetary motion also. Why, then, do we never speak of quantization of orbits of planets around the Sun? Explain.


          • 3.
            A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

              • 5 V
              • 3.5 V
              • 2.5 V
              • Zero V

            • 4.
              Four independent waves are expressed as \[ (i)\; y_1=A_1\sin\omega t, \] \[ (ii)\; y_2=A_2\sin 2\omega t, \] \[ (iii)\; y_3=A_3\cos\omega t, \] \[ (iv)\; y_4=A_4\sin\left(\omega t+\frac{\pi}{3}\right) \] The interference between two of these waves is possible in

                • (i) and (iii) only
                • (iii) and (iv) only
                • (i), (iii) and (iv) only
                • All of them

              • 5.
                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 \( F \)

                • 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

                    Comments


                    No Comments To Show