What is the main component of biogas and natural gas?

11. What is the main component of biogas and natural gas?
  A.  Ethane
  B.  Methane (Ans-B)
  C.  Propane
  D.  Butane
12. Who of the following recognized that large quantity of energy is released as a results of the fusion of hydrogen nuclei to form deuterium?
  A. Enrico Fermi(Ans-A)
  B. Glenn Seaborg
  C. Hans Bethe
  D. Werner Heisenberg
13. The phenomenon of total internal reflection is observed in which one of the following?
  A.  Glowing tube light(Ans-A)
  B.  Lightpassingthroughlens
  C.  Sparkling diamond
  D.  Twinkling star.
14. Through which one among the following materials does sound travel slowest?
  A.  Air
  B.  Glass
  C.  Water
  D.  Wood(Ans-D)
15. Which one of the following is printed on a commonly used fluorescent tube light?
  A.  220 K
  B.  273 K
  C.  65000 K(Ans-C)
  D.  9000 K