Ans: (a)
213. The radar is utilised for: [RRB 2003]
   (a) the detection of solar radiation
   (b) the observation of planets
   (c) the detection of aircrafts, ships etc and for the path indicators
   (d) the detection of the intensity of the earthquakes
Ans: (c)
214. A three dimensional photograph is prepared through: [UPPCS (Pre) 1990,
   CDS 2003]
   (a) holography
   (b) photography
   (c) photochromatic process
   (d) radiography
Ans: (a)
215. Who was the inventor of cosmic rays?
   (a) Bruno Rosi
   (b) Victor Hess
   (c) Copernicus
   (d) Edvin Hebel
Ans: (b)
216. Who designed and fabricated the first prototype of the Radar: [SSC 2000]
   (a) J.H. Van Tassel
   (b) W.c. Roentgen
   (c) ET. Phonsberth
   (d) Taylor and Young
Ans: (d)
217. Who was the inventor of gravitational laws ? [RRB Assist. Driver 2003]
   (a) Edison
   (b) Newton
   (c) Faraday
   (d) None of these
Ans: (b)