Photocells are used

A. in burglar alarms

B. in automotive devices for light switches

C. television cameras

D. All the above

Related Questions

  1. Chronometer la an instrument to measure
  2. The heat produced in a conductor due to the passage of a current through it is proportional to
  3. When we sweat, we feel comfortable under a fan because
  4. A light year means
  5. A bullet is fired at a certain angle with the horizontal. Its path will be
  6. Among the following the most suitable material for the core of an electro-magnet is
  7. The transistor was invented by
  8. The colour or an opaque object is due to the colour it
  9. Tea pots are highly polished
  10. In a river, the currents are fastest where the river la
  11. Gamma radiations are used for
  12. Acoustics' la a branch or study dealing with
  13. The light from the star nearest to the sun reaches the earth in
  14. Pyrometers are instruments used
  15. Who discovered that the Cree Call acceleration Is the same for any object at a given place?
  16. The speed of light is minimum while passing through
  17. In a hydraulic pressure
  18. A ship sailing from a river to the sea
  19. A projectile is fired at an angle with the horizontal with a small velocity. Its horizontal range will…
  20. A piece of ice is Boating In water kept in a beaker. When all the ice melts the level of water will
  21. The filament used in the electric lamp is made of
  22. In the visible spectrum which colour has the shortest wavelength?
  23. The number of galaxies that are visible without telescope on clear dark nights and away from bright…
  24. Mica is used in an electric iron because it is a
  25. When sound waves travel from one medium to another, the quantity which remains unchanged is its
  26. The mass number and the atomic number of an element are X and Y respectively. The number oC neutrons…
  27. The phenomenon of radioactivity was discovered by
  28. Choose the scalar quantity from the following physical quantities
  29. Ultrasonic waves are used
  30. Which of the following is known as freon?

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