Electrostatics

This is my lesson plan for the chapter of electrostatics.

Electrostatics- The chapter of electrostatics deals with another¹ fundamental nature of particles, “Charge”, in particular charges at rest.

This Chapter is broadly divide in nine parts, parts of the chapter and time required for each are given in sequence as per lesson plan. The time required for completion of the chapter narrowly varies around 25 hours.

1. Charge

Definition and  Properties

Definition- It includes formal definiton of charge, the idea of charged bodies, +ve and –ve charges, the transfer of charges, attraction and repulsion of charged bodies.

Properties- The charge carriers, quantisation of charges, conservation of charges. Conductors, free electons and induced charages.

2. Interaction of Charges

Coulomb’s law of electrostatic force, between two point charges. Coulomb’s law in vector form. Principle of superposition, Electrostatic force on a point charge due to surround chage distribution.

3. Electric field

Dfinition of electic field due to a point charge. Calculation of electric field at a point in space using principle of superpositon for descrete distribution and continuous distribution of chages.

Continuous Distribution of charges. (Uniform distribution of chages )

1. Rod of finite length- Calculation of electric field due to uniformly charged rod at point in space. (using calculus)
2. Ring or arc of finite radius- Calculation of elecric field due to uniforly chaged ring at a point on the axis of ring, calculation of electric field at centre of an arc. (using calculus and symmetry) Deriving symmerty betwwen above calculations.
3. Disc or Sector of finite radius -calculation of electric field at a point on the axis of disc or at the centre of a sector.( Using idea of surface chage density and calculus)
4. Hemispherical shell- Calculation of electric field at the centre of hemisphere.( using calculus)
5. Application of all above derivations in calculation of electric field using symmetry for different geometrical symmetries.

Continuous distribution of charges ( Non uniform distribution)Demonstration of concept using some problems, using calculus.

4. Electric Potential Energy

Derivation of electric potentianl energy between two point charges using work-energy theorem.  Electric potential energy of system of charges. Elecric potential energy or self energy of continuous charged bodies. Some typical problems relating work energy theorem.

5. Electric Potential

Dfinition of electic potential due to a point charge. Calculation of electric potential at a point in space using principle of superpositon for descrete distribution and continuous distribution of chages.

Continuous Distribution of charges. (Uniform distribution of chages )

1. Rod of finite length- Calculation of electric potential due to uniformly charged rod at point in space. (using calculus)
2. Ring or arc of finite radius- Calculation of elecric potential due to uniforly chaged ring at a point on the axis of ring, calculation of electric potential at centre of an arc. (using calculus)
3. Disc or Sector of finite radius -calculation of electric potential at a point on the axis of disc and on the edge of disc. Calculation of electric potential due to sector at the centre of a sector.( Using idea of surface chage density and calculus)

The relationship between change in  electric potential energy and electric potential. Some problems on the path independency of  change in potential energy.

6. Relationship between Electric field and Electric potential

Equipotential surfaces, the relationship betweeen jumping from one equipotential surface to other and electric field. Rough mathematical derivation beween electric field and electric potential. DIFFERENTIAL relationship between  and V using  (nabla)

Some problems on euipotential surfaces and electric field.

7. Electric Dipole

Definition and properties of an electric dipole, calculation of net dipole moment i.e vector addition of dipole moments, electric potential at a point in space due to a dipole. The change in position vector i.e.  along  and along . Derivation of electric field at a point in space using differential relationship betweeen  and V, along directions  and . Effects on a electric dipole placed in a uniform electric field, the net torque acting on a dipole due to external electric field, potential energy of a dipole in an external electric field. Net force and torque acting on an electric dipole placed in non uniform external electric field.

8. Gauss’ Law

Electric field line, definiton and properties. Area vector, flux , elecrtic flux. Gauss law, some problems on direct gauss law, Gauss’ law and Coulomb’s law similarities.calculation of electric flux passing through a surface for different geometrical symmetries.

Application of Gauss’ law.

Discussion of properties of a charged conductor. Calculation of electric field due  to a hollow sphere and drawing properties of spherical distribution,  calculation of electric field due to a charged solid sphere, calculation of electric field due to infinite charge distribution i.e cylindrical symmetry, planar symmetry. Calculation of electric field inside a cavity. Application of above mentioned derivations for different geometrical arrangements.

9. Capacitors

Definition of a capacitor, geometrical, and theoretical (capacitance, potential drop, charge) parameters of a capacitor. Different types of capacitors depending on their geometrical arrangements, and calculation of their capacitance. The idea of polarization, permittivity constant of space, Coulomb’s law and Gauss’ law revised. Calculation of capacitance of a capacitor including the concept of permittivity of space. Circuits of capacitors, calculation of equivalent capacitance for an arrangement of capacitors. Energy stored in the capacitors.

1 D      2 B    3 B    4 B    5 D         6 B        7 A      8 B      9 D     10 A