GK-General Science Question and Answer
GK-General Science Question and Answer
62. An ordinary tube light used for lighting purposes
contains
contains
- fluorescent material and an inert gas
- one filament, reflective material and mercury vapour
- fluorescent material and mercury vapour
- two filaments, fluorescent material and mercury vapour
63. The term ‘Black Box’ is more commonly used in relation to which of the following?
- It is a box in which high grade uranium is kept to prevent radiation.
- It is a time capsule in which records of important events are kept to be opened at a later date,
- It is a flight recorder in an aero plane.
- None of these
64. The lightning conductor used in building, protects the building by
- dissipating the electric charge away from the building
- conducting the lightning safely to the ground
- absorbing the electric charge
- None of these
65. Sodium vapour lamps are preferred over incandescent lamp because of
- higher tolerance to voltage fluctuation
- higher intensity of illumination
- easy installation
- None of these
66. The principle of working of periscope is based on
- reflection only
- refraction only
- reflection and refraction
- reflection and interference
67. The working of the quartz crystal in the watch is based on
- Johnson effect
- Photoelectric effect
- Edison effect
- Piezo electric effect
68. A handwritten message can be instantly transmitted as such to any part of the world through
- Speed post
- Telex
- Electronic mail
- FAX
69. Which of the following combinations of aperture and shutter speed of a camera will allow the maximum exposure?
- F-5.6,1/l000
- F-8,l/250
- F-16,l/l25
- F-22,1/60