Sound travels fastest in

A. air

B. water

C. iron

D. vacuum

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

You can do it
  1. The cover of a solar cooker is made of glass because
  2. Acoustics' la a branch or study dealing with
  3. Choose the correct answer
  4. A rheostat is used
  5. The unit of power in SI is
  6. The heating element often used in an electric iron is
  7. Out of the following, name the fluorescent substance.
  8. The velocity of sound in a medium is
  9. Which of the following is not electromagnetic waves?
  10. The speed of light is minimum while passing through
  11. The ozone layer absorbs
  12. When a body is immersed in a fluid the force of buoyancy of the fluid on the body depends on
  13. The extremely luminous objects located at the centre of some distant galaxies and which are sources…
  14. The mass number and the atomic number of an element are X and Y respectively. The number oC neutrons…
  15. The direction of heat flow between two objects depends on
  16. The sun continuously produces an enormous amount of energy. This la due to
  17. A cyclist leans inwards when he is negotiating a curve 10 that
  18. When we tighten the string of a sitar or tanpura its pitch
  19. The period of a geostationary (synchronous) satellite orbiting the earth over the equator la
  20. The speed of sound in air at 0° C is approximately
  21. The acoustical quality of a room depends on
  22. The theory that the earth constituted the centre of the universe around which the sun and the planets…
  23. When one enters a dark room after being in bright light one is not able to see anything clearly for…
  24. The colour or an opaque object is due to the colour it
  25. The period of oscillation of a simple pendulum depends upon
  26. X-rays are
  27. A permanent magnet may be demagnetised by
  28. Two tumblers stuck together can be separated by
  29. The radius of an atom is approximately
  30. Rays from the headlight of a motor car are rendered parallel by suitably using