Concept of magnetic dipoles

“Can u explain Concept of magnetic dipoles” – Sam Asked Answer: A magnet always exist in pairs. A magnetic dipole consists of two equal and opposite poles separated by a small distance. The magnetic poles cannot exist alone. Monopoles does not exist. A single current carrying loop is a simple practical  example for a magnetic dipole. Please refer [...]

Why does magnet attract only some of the materials like iron why not plastic ? What is the absolute reason behind it?

Why does magnet attract only some of the materials like iron why not plastic ? What is the absolute reason behind it? (Ankit Gururani posted in facebook) Answer: The answer cannot be limited to a quick reply. The cause of magnetism is revolution of electrons. A revolving electron acts like a tiny magnet just like a [...]

IMPORTANT FIVE MARKS QUESTIONS FOR CLASS XII

  1. Derive an expression for the Electric field at a point on the (i) axial line and (ii) equatorial line of an electric dipole
  2. Describe the principle construction and working of Van de Graff Generator.
  3. State Gauss’ theorem and apply it to find the electric field at a point due to
    1. A point charge
    2. A line of charge
    3. A plane sheet of charge
    4. A charged spherical conducting shell
    Derive expression for the potential energy of a system of point charges. Derive expression for the torque on a dipole in a uniform electric field. Derive expression for the work done in turning a dipole in a uniform electric field. Derive an expression for the potential energy of a dipole in a uniform electric field. Explain the principle of a parallel plate capacitor Derive an expression for the capacitance of a parallel plate capacitor.

    10.  Derive an expression for the effective capacitance when three capacitors are connected in (i) series (ii) parallel

    11.  Derive an expression for the energy stored in a parallel plate capacitor.

    12.  read more