Q1. Food gets cooked faster in a pressure cooker because
(a) water starts boiling at a lower temperature due to high pressure
(b) water starts boiling at a higher temperature due to high pressure
(c) water boils only at 100°C but the heat content is higher at high pressure
(d) convection currents are set inside the cooker
(e) None of the above
Q2. It is more comfortable to wear white cloths in summer because
(a) they reflect heat falling on them.
(b) they radiate heat tansferred from the body.
(c) they absorb perspiration.
(d) they are soothing to the eye.
(e) None of the above
Q3. The atmosphere exerts enormous pressure on us. But, we don’t feel it because
(a) our blood exerts a pressure slightly more than that of the atmosphere.
(b) we are used to it.
(c) our bones are very strong and can withstand the pressure.
(d) the surface area of our head is very small.
(e) None of the above
Q4. Which of the following organelles of a cell is involved in photosynthesis?
(a) Chloroplast
(b) Mitochondria
(c) Golgi bodies
(d) Endoplasmic reticulum
(e) None of the above
Q5. The ultimate cause of water movement in a plant stem against gravity is
(a) Osmosis
(b) Photosynthesis
(c) Transpiration
(d) Diffusion
(e) None of the above
Q6. A seed is ripened:
(a) Ovary
(b) Flower
(c) Gynoecium
(d) Ovule
(e) None of the above
Q7. Which of the following plants produce only seeds but no fruit?
(a) Sugarcane
(b) Peanut
(c) Cycas
(d) Almond
(e) None of the above
Q8. Assertion (A): Aluminium foil cannot be used in a particle scattering experiment.
Reason (R): Aluminium is highly malleable metal.
(a) Both A and R are correct. R is the correct reason for A.
(b) Both A and R are correct but R is not the correct reason for A.
(c) A is correct and R is incorrect.
(d) A is incorrect and R is correct.
(e) None of the above
Q9. Which one of the following gives the highest amount of hydrogen ions (H+)?
(a) Sodium hydroxide solution
(b) Milk of magnesia
(c) Lemon juice
(d) Gastric Juice
(e) None of the above
Q10. Which one of the following is NOT true for bleaching powder?
(a) It is used as a reducing agent in chemical industries
(b) It is used for bleaching wood pulp in paper factories
(c) It is used for disinfecting drinking water
(d) It is used for bleaching linen in textile industry
(e) None of the above
Solutions
S1.Ans. (b)
Sol. Gay-Lussac’s law gives the relationship between temperature and pressure, under conditions when the volume is kept constant mathematically, PαT. Thus, inside a pressure cooker water starts boiling at a higher temperature due to high pressure and the cooking of food is faster.
S2.Ans. (a)
Sol. The white clothes reflect heat falling on them in summer and they absorb the least from the sun.
S3.Ans. (a)
Sol. We don’t feel the atmospheric pressure because our blood exerts a pressure slightly more than that of the atmosphere.
S4.Ans. (a)
Sol. The actual site where photosynthesis occurs is the grana or thylakoid membranes of the chloroplast as the machinery for the process are embedded in the grana. Mitochondria are involved in the process of generation of energy, Golgi apparatus is involved in glycosylation and endoplasmic reticulum is involved in protein synthesis due to the presence of ribosome on the surface.
S5.Ans. (c)
Sol. The movement of water in plants is caused by transpiration, which involves the pulling of water due to cohesion-tension force or rather known as cohesion-tension theory. Osmosis is the process by which the solvent moves through a semi-permeable membrane from low concentration to high concentration. Photosynthesis is the conversion of light energy into chemical energy. Diffusion is a process which involves the movement of water from higher concentration to lower concentration.
S6.Ans. (d)
Sol. Botanically a fruit is a swollen and ripened ovary and the seeds are actually the fertilized ovules, inside which of the small embryos are nestled in.
S7.Ans. (c)
Sol. The production of naked seeds or ovules without fruits is one of the main characteristic features of Gymnosperms. Cycas sp. is a gymnosperm.
S8.Ans. (b)
Sol. Both assertion and reason is correct. Gold has a capacity of being rolled to extremely thin foil i.e. it is most maleable metal. So, it is used in a-scattering experiment.
S9.Ans. (d)
Sol. Gastric juice is responsible for breaking down foods you eat so digestion can continue in the small intestine.
S10.Ans. (a)
Sol. Bleaching powder is not used as a reduction agent in chemical industries. Reducing agent a substance that tends to bring about reduction by being oxidized and losing electrons.