As magnet moves inside solenoid, flux through individual turns of solenoid changes. Explain.

Collegedunia Team logo

Collegedunia Team

Content Curator

Assertion: An EMF is induced in a long solenoid by a bar magnet that moves while totally inside the solenoid along the axis of the solenoid.

Reason: As the magnet moves inside the solenoid the flux through individual turns of the solenoid changes.

When a magnet moves inside a solenoid, the flux through individual turns of the solenoid changes due to the following reasons:

  1. Changing magnetic field: When a magnet moves inside a solenoid, the magnetic field around the magnet changes. As a result, the magnetic flux passing through each turn of the solenoid also changes.
  2. Changing flux linkage: The magnetic field of the magnet induces an EMF in the solenoid. This EMF causes a current to flow through the solenoid. The current, in turn, generates a magnetic field that opposes the change in flux. This leads to a change in flux linkage, i.e., the number of magnetic field lines that pass through a turn of the solenoid.
  3. Induced voltage: The change in flux linkage produces an induced voltage in the solenoid. This induced voltage opposes the change in flux and, hence, the motion of the magnet. As a result, work must be done to move the magnet inside the solenoid.
  4. Faraday's Law: The above phenomena can be explained using Faraday's Law. According to this law, whenever there is a change in the magnetic field or the flux linkage, an EMF is induced in the solenoid. This EMF produces a current in the solenoid that generates a magnetic field that opposes the change in flux.
  5. Uses of solenoid: Solenoids are widely used in various electrical and electronic devices, such as relays, electromagnets, doorbells, and speakers. They are also used in medical devices, such as magnetic resonance imaging (MRI) machines, and in particle accelerators, such as the Large Hadron Collider (LHC).

(Note: the answer would change if the solenoid is not long)

Also check:

CBSE CLASS XII Related Questions

  • 1.
    A wire of length \(L\) is bent round into (i) a square coil having \(N\) turns and (ii) a circular coil having \(N\) turns. The coil in both cases is free to turn about a vertical axis coinciding with the plane of the coil, in a uniform, horizontal magnetic field and carry the same currents. Find the ratio of the maximum value of the torque acting on the square coil to that on the circular coil.


      • 2.

        (I) The real image of an object placed between $f$ and $2f$ from a convex lens can be seen on a screen placed at the image location. If the screen is removed, is the image still there? Explain.

        (II) Plane and convex mirrors produce virtual images of objects. Can they produce real images under some circumstances? Explain.


          • 3.
            Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

              • \( (M_x - M_z)<M_y \)
              • \( (M_x - M_y)<M_z \)
              • \( M_x>(M_y + M_z) \)
              • \( M_x<(M_y + M_z) \)

            • 4.

              An electron is revolving around a proton in a circular orbit of radius $r$. Using classical physics, prove that the ratio of value of the angular momentum and the value of magnetic moment of electron revolving in the orbit is a constant.


                • 5.

                  Find the ratio $\dfrac{\lambda_\alpha}{\lambda_p}$ of the de Broglie wavelength $\lambda_\alpha$ associated with an alpha particle to the de Broglie wavelength $\lambda_p$ associated with a proton if both are moving with the same velocity.


                    • 6.

                      A ray of light MN is incident normally on the face corresponding with side AB of a prism with an isosceles right-angled triangular base ABC. Trace the path of the ray as it passes through the prism when the refractive index of the prism material is (i) $\sqrt{2}$, and (ii) $\sqrt{3}$.

                        CBSE CLASS XII Previous Year Papers

                        Comments


                        No Comments To Show