Derive an expression for the apparent frequencies when source and observer moving in the same direction.

Derive an expression for resonant frequency.

Derive an expression for the apparent frequencies when the medium of source is at rest, observer in motion.

What is Doppler's effect? Derive an expression for the apparent frequencies when the medium at source is in motion, observe at rest.

Derive an expression for the equivalent capacitance when capacitors are connected in parallel.

Derive an expression for centripetal force acting on a body moving in a circular path. Is any work done by centripetal force ? Explain.

An electric dipole of small length lies along X-axis of a coordinates system. Derive an expression for the magnitude of electric field E due to the dipole at any point on its equatorial line. Mention its direction.