What are the important derivations for …

Coulomb’s law of Electrostatics ( Normal Derivation & Vector Derivation F21=- F12) 3 - Superposition Principal in Electric Field Intensity 7 Note : Electric Lines of force and it’s properties is very important 8 - Electric field intensity of a dipole at tanA/ Equatorial position 10 - Electric field intensity of a dipole at tanB/ Axial position 11 - Electric field intenisty at any point due to an ideal dipole 12 - Force and torque acting on a dipole in an external uniform electric field 13 - Work done to rotate a dipole in external electric uniform field 14 - Gauss Theorem : It’s definition, verificaiton and application 17 - Electric field intensity due to a thin uniformly charged infinite plane sheet 19 - Electric field intensity due to a uniformly charged spherical shell 20 - Electric Potential at a point due to a point charge 22 - Prove electric field is conservative in nature 25 - Capacitance of a parallel plate capacitor 29 - Capacitance of a single and concentric sphere 30 - Energy stored in a capacitor 31 - Series and Parallel Combination of Capacitors 33 - Effect of dieletric medium on the capacitance of parallel plate capacitor

There are a lot. I'm too lazy to write all of that...