A photon is

A. a quantum of electromagnetic radiation

B. light source used in photography

C. a photo film

D. sun-light

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  1. Which is the densest planet of the solar system?
  2. When water is cooled from 4C to 2C its density
  3. The difference between planets and stars is
  4. Meteors
  5. A simple mercury barometer is found in a slightly slanting position. The atmospheric pressure
  6. The device used to record the sound is
  7. A pair of stars that revolve round each other is
  8. A man stands in a lift which accelerates upwards. The resultant reaction force on the floor of the lift…
  9. If an object is placed between two parallel plane mirrors, the number of images formed will be
  10. A permanent magnet may be demagnetised by
  11. Red Light is used as a dancer signal because
  12. The focal length or lens or the eye is under the control or the
  13. The overhead wires supported by high towers in the grid system carry
  14. Every action has an equal and opposite reaction is Newton's law of Motion
  15. Which of the following is known as freon?
  16. Heat transfer
  17. When a bullet is fired from a gun
  18. An astronomical unit of distance is
  19. Tea pots are highly polished
  20. Air pressure is usually highest when the air is
  21. Photocells are used
  22. Fish and other aquatic creatures can live inside a deep frozen pond because
  23. The planet with the reddish tinge is
  24. During thunder storm you are travelling in a car. To protect yourself from the lightning you will have…
  25. In the electrical circuit of a house the fuse acts as
  26. Sun spots are
  27. Commonly used safety fuse wire is made of
  28. The filament lamp is an example for
  29. A cup of hot coffee is placed on a metal table in a room. By which of the following methods does it…
  30. Mercury is used in thermometers because