16.Two earths satellites are revolving in the same circular orbit round the centre of the earth. They must have the same:

17.The time period of a satellite of earth is 5 h. If the separation between the earth and the satellite is increased to 4 times the previous value, the new time period will become:

18.If the radius of the earth reduces by 4%, density remaining the same, then the escape velocity will:

19.The time period of an earths satellite in circular orbit is independent of:

20.When a satellite going round the earth in a circular orbit of radius r and speed v loses some of its energy, then r and v change as: