1. Fruits stored in a cold chamber exhibit longer storage life because
a) exposure to sunlight is prevented
b) the concentration of carbon dioxide in the environment in increased
c) rate of respiration is decreased
d) there is an increase in humidity
2. Ball bearings are used in bicycles, cars, etc., because
a) the actual area of contact between the wheel and axle is increased
b) the effective area of contact between the wheel and axle is increased
c) the effective area of contact between the wheel and axle is reduced
d) None of the above statements is correct
3. Consider the following statements:
1. Size of the sun at dusk
2. Colour of the sun at dawn
3. Moon being visible at dawn
4. Twinkle of stars in the sky
5. Polestar being visible in the sky
Which of the above are optical illusions?
a) 1, 2 and 3
b) 3, 4 and 5
c) 1, 2 and 4
d) 2, 3 and 5
4. Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?
1. Dispersion
2. Refraction
3. Internal reflection
Select the correct answer using the codes given below:
a) 1 and 2 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
5. Many transplanted seedlings do not grow because
a) the new soil does not contain favorable minerals
b) most of the root hairs grip the new soil too hard
c) most of the root hairs are lost during transplantation
d) leaves get damaged during transplantation
6. Which of the following statements is/are correct?
1. Viruses lack enzymes necessary for the generation of energy
2. Viruses can be cultured in any synthetic medium.
3. Viruses are transmitted from one organism to another by biological vectors only
Select the correct answer using the codes given below.
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
7. The known forces of nature can be divided into four classes, viz., gravity, electromagnetism, weak nuclear force, and strong nuclear force. With reference to them, which one of the following statements is not correct?
a) Gravity is the strongest of the four.
b) Electromagnetism acts only on particles with an electric charge
c) Weak nuclear force causes radioactivity
d) Strong nuclear force holds protons and neutrons inside the nucleus of an atom
8. The efforts to detect the existence of Higgs boson particles have become frequent news in the recent past.
What is the importance/importance of discovering this particle?
1. It will enable us to understand why elementary particles have mass.
2. It will enable us in the near future to develop the technology of transferring matter from one point to another without traversing the physical space between them.
3. It will enable us to create better fuels for nuclear missions.
Select the correct answer using the codes given below:
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
9. Mycorrhizal biotechnology has been used in rehabilitating degraded sites because mycorrhiza enables the plants to
1. Resist drought and increase the absorptive area
2. Tolerate extremes of pH
3. Resist disease infestation
Select the correct answer using the codes given below:
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
10. Recombination DNA technology (Genetic Engineering) allows genes to be transferred
1. across different species of plants
2. from animals to plants
3. from microorganisms to higher organisms Select the correct answer using the codes given below.
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
11. Which of the following diseases can be transmitted from one person to another through tattooing?
1. Chikungunya
2. Hepatitis B
3. HIV-AIDS
Select the correct answer using the codes given below:
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
12. Consider the following minerals:
1. Calcium
2. Iron
3. Sodium
Which of the minerals given above is/are required by the human body for the contraction of muscles?
a) 1 only
b) 2 and 3 only
c) 1 and 3 only
d) 1, 2 and 3
Answer:
1-C; 2-C; 3-C; 4-D;5-C;
6-A; 7-A; 8-A; 9-D; 10-D;
11-B; 12-D;
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