3686: Suppose a rocketship is receding from the earth at a speed of 2/10th the velocity of light. A light in the rocketship appears blue to the passengers on the ship. What colour would it appear to an observer on the earth?
(a) Blue
(b) Orange
(c) Yellow
(d) Yellow-orange
3687: Acid precipitation is now regarded as a serious problem in some European and Asian countries. Its major cause or source is
(a) discharge of acidic effluents onto neutral or slightly alkaline land where the acidic components precipitate
(b) emissions of sulphur oxides and nitrogen oxides from thermal power plants and burning of fossil fuels; these oxides dissolve in atmospheric water vapour and fall back on earth as acid rain
(c) natural carbon dioxide released during respiration of living organisms dissolves in water, forming carbonic acid which is the chief contributor to acidity in rain water
(d) chloro-fluoro-carbons readily react with various chemicals near the earth's surface, producing acidic intermediates which cause acid precipitation
3688: People drinking water from a shallow hand pump are likely to suffer from all of the following diseases except
(a) Cholera
(b) Typhoid
(c) Jaundice
(d) Fluorosis
3689: Consider the decadal Census data given below:
Decadal Population (in millions)
Year---Population
1961--- 10.7
1971--- 14.3
1981--- 16.2
1991--- 18.9
The above data refer to which one of the Population by Religion Groups ?
(a) Sikhs
(b) Jains
(c) Christians
(d) Buddhists
3690: "Each day is more or less the same, the morning is clear and bright with a sea breeze; as the Sun climbs high in the sky, heat mounts up, dark clouds form, then rain comes with thunder and lightning. But rain is soon over." Which of the following regions is described in the above passage?
(a) Savannah
(b) Equatorial
(c) Monsoon
(d) Mediterranean