586: The planet Mercury is revolving in an elliptical orbit around the sun as shown in the given figure. The kinetic energy of mercury is greatest at the point labelled
(a) A
(b) B
(c) C
(d) D
Explanation:
The velocity of rotation is maximum at the nearest point 'A' therefore the Kinetic Energy is also maximum at this point. Also, the Kinetic Energy is lowest at the farthest point 'B' as the velocity is minimum at that point.
587: Which one of the following is the best strategy for environment-friendly sustainable development in Indian agriculture?
(a) Expansion of cultivable land, increased use of superphosphate, urea and effective biocides
(b) Wider popularization of high-yielding crop varieties, better and more frequent irrigation and increased frequency of aerial sprays of inorganic fertilizers and pesticides
(c) Mixed cropping, organic manures, nitrogen-fixing plants and pest resistant crop varieties
(d) Improved farm implements and machinery, use of potent insecticides to minimise post-harvest grain losses and mono culture cropping practices
588: Recently, there has been a concern over the short supply of a group of elements called 'rare earth metals'. Why?
1. China, which is the largest producer of these elements, has imposed some restrictions on their export.
2. Other than China, Australia, Canada and Chile, these elements are not found in any country.
3. Rare earth metals are essential for the manufacture of various kinds of electronic items and there is a growing demand for these elements.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Explanation:
As defined by IUPAC, rare earth elements ("REEs") or rare earth metals are a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrum.
The 17 rare earth metals, including dysprosium and neodymium, are essential components in modern technology such as iPhones, wind turbines, halogen lights and even precision-guided missiles. China produces more than 95pc of these minerals and it has imposed a quota restriction on their export
589: Consider the following areas:
1. Bandipur
2. Bhitarkanika
3. Manas
4. Sunderbans
Which of the above are Tiger Reserves?
(a) 1 and 2 only
(b) 1, 3 and 4 only
(c) 2, 3 and 4 only
(d) l, 2, 3 and 4
Explanation:
There are 53 tiger reserves in India as on (21-6-2011) which are governed by Project Tiger which is administered by the National Tiger Conservation Authority. There were an additional six proposed and four approved in principle reserves that are not yet declared.
Among these 1, 3 and 4 are tiger reserve.
Bhitarkanika is a unique habitat of Mangrove Forests in Orissa.
590: Consider the following
1. India does not have any deposits of Thorium.
2. Kerala's monazite sands contain Uranium.
Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 & 2
(d) Neither 1 nor 2
Explanation:
Under the US Geological Survey Estimate, Australia and India Have Particularly large reserves of thorium. India and Australia are believed to possess approx 300,000 metric tonnes each; each country possessing 25% of the world's thorium reserves. Furthermore the IAEA report mentions that India possesses two thirds (67%) of global reserves of monazite, the primary thorium ore.
The coastal belt of Karunagappally, Kerala is known for high background radiation (HBR) from thorium-containing monazite sand.