What are Thick and Thin spherical lenses?

Electric field intensity at an outside point of a charged thin spherical shell is

State Gauss's law of electrostatics. Using it derive field due to a uniformly charged thin spherical shell.

What is meant by the statement, ''the electric field of a point charge has spherical symmetry, whereas that of an electric dipole is cylindrically symmetric'' ?

Why are small drops of a liquid spherical ?

Answer in one word/ one sentence / state/ define. When you look through a spherical mirror your face appears diminished. What type of spherical mirror is used?