CTET Solved Paper - REET Feburary 2016
PART V
Environmental Studies
91. Concave mirror can form image when the object is placed very close to the mirror
- Option : B
- Explanation : When a ray of light which is parallel to the principal axis and another ray which is passing through the centre of curvature, retraces its path and other ray which is parallel to the principal axis, after reflection passes through the focus. These rays appear to meet behind the mirror when the reflected rays are extended backwards. The image is virtual, erect and magnified.
92. Which of the following is one of three biodiversity hot spots of India?
- Option : C
- Explanation : A biodiversity hot spot is a biogeographic region with a reservoir of biodiversity that is under threat from humans. India has two major hot spots. The rate of deforestation in these areas is very high and ecosystems have reached at a fragile stage. These two areas are the Western Ghats and the Eastern Himalayas. In Eastern Himalayas there are an estimated 10,000 species of plants, of which one third are endemic and found nowhere else in the world.
93. Which is the state animal of Rajasthan?
- Option : C
- Explanation : The Rajasthan Government was decided in July 2014 to declare camel as Rajasthan's State animal, at a Cabinet meeting held in Bikaner. Camel is mainly found in Thar desert area of the state and provides livelihood to a large number of people in rural areas.
94. Which statement is correct in the following?
- Option : A
- Explanation : All metals are tensile. The term tensile strength refers to the amount of tensile (stretching) stress a material can withstand before breaking or failing. The ultimate tensile strength of a material is calculated by dividing the area of the material tested (the cross-section) by the stress placed on the material, generally expressed in terms of pounds or tons per square inch of material.
95. Which is not a source of air pollution?
- Option : C
- Explanation : There are four main types of air pollution sources:
Mobile Sources Such as automobiles i.e. cars, buses, planes, trucks and trains.
Stationary Sources Such as power plants, oil refineries, industrial facilities and factories.
Area Sources Such as agricultural areas, cities and wood burning firep laces.
Natural Sources Such as windblown dust, wildfires and volcanoes.
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