SONAR (Sound Navigation Ranging) is

A. used by warships and military aircraft to locate enemy submarines

B. used by ships to determine the depth of water beneath them

C. a detective device that uses sound to locate under - water objects

D. All the above

Please do not use chat terms. Example: avoid using "grt" instead of "great".

You can do it
  1. The source of electric energy in an artificial satellite is
  2. When light travels from one medium to another there is a change in its
  3. A body has fallen from a height. Just before touching the pound it has
  4. Pieces of camphor placed on water move about rapidly. This is because of
  5. A ship sailing from a river to the sea
  6. When a steel ball is placed on the surface of mercury, it does not sink because
  7. Primary colours are
  8. Which of the following is wrongly matched?
  9. The fact that two large ships travelling on close parallel courses in the same direction tend to move…
  10. The rocket engine is motivated by jet propulsion which uses the famous
  11. A temperature below absolute zero for an ideal gas
  12. When a satellite la In a geostationary orbit the force keeping it in orbit Is
  13. When ice just melts
  14. The following are the atmospheric zones above the surface of the earth:A) Troposphere B) IonosphereC)…
  15. The velocity of sound in air
  16. Sound waves in air are
  17. When a swing la drawn to a side Its potential energy In relation to the earth
  18. The study of astronomy include a
  19. Which mirror is used as a rear view mirror in Vehicles?
  20. If an empty cylinder Is half ruled with a liquid, Its centre of gravity is
  21. A person cups his hand around the mouth when shouting. Why?
  22. Water has maximum density at
  23. Cosmic rays are
  24. Formation of shadows can be explained by
  25. Which of the following sets of elementary particles have nearly equal masses?
  26. A solar eclipse occurs when the earth, the sun and the moon are in a straight line, and
  27. A lactometer la used to
  28. The planet with the reddish tinge is
  29. The electron has a mass equal to
  30. The velocity of sound in a medium is