In an experiment a student observed the magnification produced by three mirrors A, B and C. It is found that A produces constant magnitude of magnification with same sign always while B produces magnifications of different magnitudes and sign depending on the position of the object. Mirror C produces magnifications of different magnitudes depending on the position of the object with same sign always. The mirror A, B and C respectively a) plane mirror, concave mirror, convex mirror
b) plane mirror, concave mirror, plane mirror
c) convex mirror, plane mirror, concave mirror
d)concave mirror, convex mirror, plane mirror

Answer: buoyancy forceexplanation: in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -

Wish i knew this to !