What is Archemedic's principle.

What is Huygen's principle? Show that at a larage distace from the source, a small portion of the spherical wave can be approximated by a plane wave.

What is the basci principle of a moving coil galvanometer? Derive an expression for current flowing through the galvanometer in terms of steady angular deflection of its coil. Define voltage. Sensitivity of the galvanometer. What is a convenient way to increase its sensitivity?

What chemical principle is involved in choosing a reducing agent for getting the metal from its oxide ore? Consider the metal oxide Al_2O_3 and Fe_2O_3 and Justifuy the choice of the reducing agent.

What is the principle of calorimetry?

What is the principle of a meter bridge.

What is the principle employed in a mass spectrometer?

Does Archimedes' principle hold in a vessel in free fall or in a satellite moving in a circular orbit