Ans : (a)
272. Which one of the following is a good conductor of electricity? [NDA 2008]
          (a) Shellac
          (b) Human body
          (c) Glass
          (d) Ebonite
Ans : (b)
273. Which one of the following common devices works on the basis of the principle of mutual induction? [CDS 2008]
          (a) Tube light
          (b) Transformer
          (c) Photodiode
          (d) LED
Ans : (b)
274. On which one of the following conservation laws, does a rocket work? [CDS 2008]
          (a) Mass
          (b) Energy
          (c) Linear momentum
          (d) Angular momentum
Ans : (d)
275. The phenomenon of ‘total internal reflection’ is observed in which one of the following? [Asstt Comm 2008]
          (a) Glowing tube light
          (b) Light passing through lens
          (c) Sparkling diamond
          (d) Twinkling star
Ans : (a)
276. Through which one among the following materials does sound travel slowest? [Asstt Comm 2008]
          (a) Air
          (b) Glass
          (c) Water
          (d) Wood
Ans : (d)
277. Who of the following recognized that large quantity of energy is released as a result of the fusion of hydrogen nuclei to form
     deuterium? [Asstt Comm 2008]
          (a) Enrico Fermi
          (b) Glenn Seaborq
          (c) Hans Bethe
          (d) Werner Heisenberg
Ans : (a)
278. Consider the following statements:
          1) If magenta arid yellow coloured circles intersect, the intersected area will have red colour.
          2) If cyan and magenta coloured circles intersect, the intersected area will have blue colour.
          Which of the statements given above is/are correct? [IAS 2007)
          (a) 1only
          (b) 2 only