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EEE :: Electric Illumination

  1. Melting temperature of tungsten is
  2. A.
    2000°K
    B.
    2500°K
    C.
    2655°K
    D.
    3655°K

  3. A zero watt lamp consumes
  4. A.
    no power
    B.
    about 5 to 7 W power
    C.
    about 15 to W power
    D.
    about 25 to 30 W power

  5. The output of a tungsten filament lamp depends on
  6. A.
    size of lamp
    B.
    size of shell
    C.
    temperature of filament
    D.
    all of the above

  7. Which bulb operates on lowest power ?
  8. A.
    Night bulb
    B.
    Neon bulb
    C.
    GLS bulb
    D.
    Torch bulb

  9. Which gas is sometimes used in filament lamps ?
  10. A.
    Argon
    B.
    Krypton
    C.
    Nitrogen
    D.
    Carbon dioxide

  11. Candela is-the unit for
  12. A.
    Light flux
    B.
    Luminous intensity
    C.
    Brightness
    D.
    Luminous efficiency

  13. Lumen/watt is the unit of
  14. A.
    Light flux
    B.
    Luminous intensity
    C.
    Brightness
    D.
    Luminous efficiency

  15. Light is produced in electric discharge lamps by
  16. A.
    heating effect of current
    B.
    magnetic effect of current
    C.
    ionization in a gas or vapor
    D.
    carbon electrodes

  17. The color temperature of day light is around
  18. A.
    50 K
    B.
    160 K
    C.
    600 K
    D.
    6000 K

  19. Which photometer depends for its operation on Inverse Square Law ?
  20. A.
    Guilds Flicker Photometer
    B.
    Lummer Brodhum Photometer
    C.
    Macbeth llluminometer
    D.
    Trotter Illumination Photometer