The wireless system is operating at 2GHz. A base station and a mobile unit are separated by 16km. The maximum gain of the transmitting antenna at the base station is 20dB. The input power to the transmitter is 100W, and the power received by the antenna is 5nW. The antennas are aligned, and there are no re ections or loses. What will be the received power if the distance between the mobile unit and the base station increases to 20km?

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 -