11. | The period of a satellite in a circular orbit of radius R is T. The period of another satellite in circular orbit of radius 4R is (a) T/4 (b) 8T (c) 2T (d) T/8 |

12. | A planet moves around the sun. At a point A, it is closest from the Sun at a distance d (a) (b) (c) (d) |

13. | The period of geostationary artificial satellite of earth is (a) 6 hours (b) 12 hours (c) 24 hours (d) 365 days |

14. | If ‘r’ represents the radius of the orbit of a satellite of mass ‘m’ moving round a planet of mass ‘M’, the velocity of the satellite is given by (a) v (b) v (c) v = (d) v = |

15. | A missile is launched with a velocity less than the escape velocity. The sum of its kinetic and potential energy is (a) Positive (b) Negative (c) Zero (d) may be positive or negative |

16. | The escape velocity of projection from the earth is approximately (R = 6400 km) (a) 7 km/sec (b) 112 km/sec (c) 12.2 km/sec (d) 1.1 km/sec |

17. | If the earth is 1/4 (a) 1/4 of the present year (b) 1/6 of the present year (c) 1/8 of the present year (d) 1/16 of the present year |

18. | The relation between escape velocity and orbit velocity is (a) v (b) v (c) v (d) v |

19. | There is no atmosphere on the moon because (a) it is closer ot the earth (b) it revolves round the earth (c) it gets light from the sun (d) the escape velocity of gas molecules is less than their root mean square velocity here |

20. | If the radius of the earth were to shrink by 1% its mass remaining the same, the acceleration due to gravity on the earth’s surface would (a) decrease by 2% (b) remain unchanged (c) increase by 2% (d) will increase by 9.8% |

Answer

11. Ans.: (b)

12. Ans.: (a)

13. Ans.: (c)

14. Ans.: (c)

15. Ans.: (b)

16. Ans.: (c)

17. Ans.: (c)

18. Ans.: (a)

19. Ans.: (d)

20. Ans.: (c)