Deep (gt500 m) in the oceans, the environment is perpetually dark and its inhabitants are not aware of the existance of a celestial source of energy called sun? what, then is their source of energy ?

What is the source of energy of sun or stars ?

State the working of a.c. generator with the help of a labelled diagram. The coil of an a.c. generator having N turns, each of area A, is rotated with a constant angular velocity omega . Deduce the expression for the alternating e.m.f. generated in the coil. What is the source of energy generation in this device?

A parallel plate vacuum capacitor eith plate area A and separation x has charges +Q and -Q on its plates. The capacitor is disconnected from the source of charge, so the charge on each plate remains fixed. a. What is the total energy stored in the capacitor? b. The plates are pulled apart an additional distance each case. c. If F is the force with which the plates attract each other, the change in the stored energy must equal the work dW =F dx done in pulling the plates apart. Find an expression for F d. Energy storage in a capacitor can be limited by the maximum electric field between the plates. What is the ratio of the electric field for the series for parallel combinations?