Home

A person cups his hand around the mouth when shouting. Why?

A. Sound energy from his mouth is then directed in one direction

B. The cupped hand acts as a cardboard tube of short length

C. The pitch of sound increases

D. Both (a) and (b)

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

You can do it
  1. Photo-electric cells convert
  2. Drinks kept in a vacuum flask remain hot or cold as the case may be for a long time because
  3. Who discovered that the Cree Call acceleration Is the same for any object at a given place?
  4. Acoustics' la a branch or study dealing with
  5. In the electrical circuit of a house the fuse acts as
  6. The world's first artificial satellite Sputnik I was launched by Russia in
  7. Resistance is measured in
  8. For an electron orbiting in a hydrogen atom, the necessary centripetal force keeping it in orbit is…
  9. The colour of a star is an indication of its
  10. Water kept in an earthen pot is less cool on rainy days than in summer because during the rainy days
  11. Cosmic rays contain
  12. In a dynamo
  13. A timer in a race is at the finish line. He should start his stop watch
  14. If a band is played on the moon the sound will
  15. A bar magnet tied in the middle with a thread is suspended at the South Pole of the earth. The magnet…
  16. The solar wind is composed of
  17. Which force is used when milk is churned to separate cream?
  18. A tube light works on the principle of
  19. Nuclear fission process means
  20. The neutron, one of the constituent particles of which the nuclei of atoms are composed was discovered…
  21. A photon is
  22. When a body is immersed in a fluid the force of buoyancy of the fluid on the body depends on
  23. In a refrigerator, the refrigerant is
  24. In a freezer ice cubes will be formed more quickly in trays made of
  25. The planet that spins Caster than any other planet is
  26. Powder clings to the skin because of
  27. An electric kettle used for boiling hard water has a white scale deposited on its heating element. This…
  28. The temperature of a large bucket-full of hot water (a few degrees below boiling point) is lower than…
  29. The coil of an electric heater is made of
  30. We see the sun before it actually rises on the horizon. This is due to