418. The device for tracking and locating the position of a moving object in
   space is called
   (a) Space ship
   (b) Lunar module
   (c) Radar
   (d) Rocket
Ans: (c)
419. The rocket engine is motivated by jet propulsion which uses the famous
   (a) Kepler"s Laws
   (b) Newtonian Third Law of Motion
   (c) Bernoulli"s Principle
   (d) Law of Relativity
Ans: (b)
420. The world"s first artificial satellite Sputnik I was launched by Russia in
   (a) 1985
   (b) 1957
   (c) 1959
   (d) 1960
Ans: (b)
421. The velocity required to place a vehicle in orbit round the moon is
   _________ that required to place it in orbit round the earth.
   (a) less than
   (b) greater than
   (c) equal to
   (d) greater than or equal to
Ans: (a)
422. When the earth reaches its perihelion
   (a) it is nearest to the moon
   (b) it is nearest to the sun
   (c) it is nearest to Pluto
   (d) it is farthest from the sun
Ans: (b)