81) Regular intake of fresh fruits and vegetables is recommended in the diet since they are a good source of antioxidants. How do antioxidants help a person maintain health and promote longevity?
(a)  They activate the enzymes necessary for vitamin synthesis in the body and help prevent vitamin deficiency
(b)  They prevent excessive oxidation of carbohydrates, fats and proteins in the body and help avoid unnecessary wastage of energy
(c)  They neutralize the free radicals produced in the body during metabolism
(d)  They activate certain genes in the cells of the body and help delay the ageing process


82) The jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation?
1.   There are no clouds or water vapour in the lower stratosphere.
2.   There are no vertical winds in the lower stratosphere.

Which of the statements given above is/are correct in this context ?
(a)  1 only
(b)  2 only
(c)  Both 1 and 2
(d)  Neither 1 nor 2



83) The function of heavy water in a nuclear reactor is to
(a)  Slow down the speed of neutrons
(b)  Increase the speed of neutrons
(c)  Cool down the reactor
(d)  Stop the nuclear reaction



84) In the context of global oil prices, "Brent crude oil" is frequently referred to in the news. What does this term imply ?
1.   It is a major classification of crude oil.
2.   It is sourced from North Sea.
3.   It does not contain sulphur.

Which of the statements given above is/are correct ?
(a)  2 only
(b)  1 and 2 only
(c)  1 and 3 only
(d)  1, 2 and 3


85) A company marketing food products advertises that its items do not contain trans-fats. What does this campaign signify to the customers ?
1.   The food products are not made out of hydrogenated oils.
2.   The food products are not made out of animal fats/oils.
3.   The oils used are not likely to damage the cardiovascular health of the consumers.

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


86) An artificial satellite orbiting around the Earth does not fall down. This is so because the attraction of Earth
(a)  does not exist at such distance
(b)  is neutralized by the attraction of the moon
(c)  provides the necessary speed for its steady motion
(d)  provides the necessary acceleration for its motion



87) What is the difference between asteroids and comets ?
1. Asteroids are small rocky planetoids, while comets are formed of frozen gases held together by rocky and metallic material.
2. Asteroids are found mostly between the orbits of Jupiter and Mars, while comets are found mostly between Venus and Mercury.
3. Comets show a perceptible glowing tail, while asteroids do not.

Which of the statements given above is/are correct ?
(a)  1 and 2 only
(b)  1 and 3 only
(c)  3 only
(d)  1, 2 and 3


88) Aspartame is an artificial sweetener sold in the market. It consists of amino acids and provides calories like other amino acids. Yet, it is used as a low-calorie sweetening agent in food items. What is the basis of this use ?
(a)  Aspartame is as sweet as table sugar, but unlike table sugar, it is not readily oxidized in human body due to lack of requisite enzymes
(b)  When aspartame is used in food processing, the sweet taste remains, but it becomes resistant to oxidation
(c)  Aspartame is as sweet as sugar, but after ingestion into the body, it is converted into metabolites that yield no calories
(d)  Aspartame is several times sweeter than table sugar, hence food items made with small quantities of aspartame yield fewer calories on oxidation



89) A married couple adopted a male child. A few years later, twin boys were born to them. The blood group of the couple is AB positive and O negative. The blood group of the three sons is A positive, B positive, and O positive. The blood group of the adopted son is
(a)  O positive
(b)  A positive
(c)  B positive
(d)  Cannot be determined on the basis of the given data



90) The surface of a lake; is frozen in severe winter, but the water at its bottom is still liquid. What is the reason ?
(a)  Ice is a bad conductor of heat
(b)  Since the surface of the lake is at the same temperature as the air, no heat is lost
(c)  The density of water is maximum at 4°C
(d)  None of the statements (a), (b) and (c) given above is correct