question_answer

Choose the correct alternatives : (i) If the gravitational potential energy of two mass points infinite distance away is taken to be zero, the gravitational potential energy of a galaxy is (positive/negative/zero). (ii) The universe on the large scale is shaped by (gravitational/electromagnetic) forces, on the nuclear scale by (gravitational/ electromagnetic/ strong nuclear) forces.

Answer:

                (i) The gravitational potential energy of a galaxy is negative because it is a bound system. (ii) The universe on the large scale is shaped by gravitational forces, on the atomic scale by electromagnetic forces and on the nuclear scale by strong nuclear forces.