State the number of significant figures in the following:
[question] Question. State the number of significant figures in the following: (a) $0.007 \mathrm{~m}^{2}$ (b) $2.64 \times 10^{24} \mathrm{~kg}$ (c) $0.2370 \mathrm{~g} \mathrm{~cm}^{-3}$ (d) $6.320 \mathrm{~J}$ (e) $6.032 \mathrm{~N} \mathrm{~m}^{-2}$ (f) $0.0006032 \mathrm{~m}^{2}$ [/question] [solution] solution: (a) Answer: 1 The given quantity is $0.007 \mathrm{~m}^{2}$. If the number is less than one, then all zeros on the right of the decimal point (but left to the first non-zero) are in...
Read More →Do you know of any activity which may be polluting this water source?
[question] Question. Do you know of any activity which may be polluting this water source? [/question] [solution] Solution: The discharge of waste water from homes, industries, hospitals, etc. into the river pollutes this fresh water source. [/solution]...
Read More →What is the major source of fresh water in the city/town/village where you live?
[question] Question. What is the major source of fresh water in the city/town/village where you live? [/question] [solution] Solution: River is a major source of fresh water [/solution]...
Read More →Why do organisms need water?
[question] Question. Why do organisms need water? [/question] [solution] Solution: Organisms need water for the following reasons: (i) All cellular processes need water as a medium. Usually, the reactions that take place in our body or within the cells occur between substances that are dissolved in water. (ii) Since most of the substances are transported in a dissolved form, water is necessary. [/solution]...
Read More →Answer the following:
[question] Question. Answer the following: (a) You are given a thread and a metre scale. How will you estimate the diameter of the thread? (b) A screw gauge has a pitch of 1.0 mm and 200 divisions on the circular scale. Do you think it is possible to increase the accuracy of the screw gauge arbitrarily by increasing the number of divisions on the circular scale? (c) The mean diameter of a thin brass rod is to be measured by vernier callipers. Why is a set of 100 measurements of the diameter expe...
Read More →“The impact of globalisation has not been uniform.”
[question] Question. “The impact of globalisation has not been uniform.” Explain this statement. [/question] [solution] Solution: “The impact of globalisation has not been uniform”. The truth of this statement can be verified if we observe the impact of MNCs on domestic producers and the industrial working class. Small producers of goods such as batteries, capacitors, plastics, toys, tyres, dairy products and vegetable oil have been hit hard by competition from cheaper imports. Also, workers are...
Read More →List any three human activities that you think would lead to air pollution
[question] Question. List any three human activities that you think would lead to air pollution. [/question] [solution] Solution: The following three human activities would lead to air pollution: (i) Burning of fossil fuels such as coal and petroleum (ii) Industrialization (iii) Deforestation [/solution]...
Read More →Why do developed countries want developing countries to liberalise their trade and investment?
[question] Question. Why do developed countries want developing countries to liberalise their trade and investment? What do you think should the developing countries demand in return? [/question] [solution] Solution: Developed countries want developing countries to liberalise their trade and investment because then the MNCs belonging to the developed countries can set up factories in less-expensive developing nations, and thereby increase profits, with lower manufacturing costs and the same sale...
Read More →How are clouds formed?
[question] Question. How are clouds formed? [/question] [solution] Solution: During day time, on being heated, a large amount of water evaporates from various water bodies and goes into the air. A part of this water vapour also reaches the atmosphere through biological activities such as transpiration and respiration. This causes the air in the atmosphere to heat up. When this heated air rises, it expands and cools, which results in the condensation of water vapour forming water droplets. The pr...
Read More →Write a note on the role of cooperatives in providing food and related items.
[question] Question. Write a note on the role of cooperatives in providing food and related items. [/question] [solution] Solution: Along with the government, cooperatives are also playing an important role in ensuring food security in India, especially in the southern and western parts of the country. The cooperative societies set up shops to sell low-priced goods to the poor. Out of all fair-price shops running in Tamil Nadu, around 94 per cent are being run by cooperatives. Mother Dairy, in D...
Read More →What are the various ways in which MNCs set up, or control, production in other countries?
[question] Question. What are the various ways in which MNCs set up, or control, production in other countries? [/question] [solution] Solution: The various ways in which MNCs set up, or control, production in other countries are by buying out domestic companies or making the latter work for them. Sometimes, MNCs buy mass produce of domestic industries, and then sell it under their own brand name, at much higher rates, in foreign countries. MNCs look towards developing nations to set up trade be...
Read More →Which of the following is the most precise device for measuring length:
[question] Question. Which of the following is the most precise device for measuring length: (a) a vernier callipers with 20 divisions on the sliding scale (b) a screw gauge of pitch 1 mm and 100 divisions on the circular scale (c) an optical instrument that can measure length to within a wavelength of light ? [/question] [solution] solution: A device with minimum count is the most suitable to measure length. (a) Least count of vernier callipers $=1$ standard division $(S D)-1$ vernier division ...
Read More →What are the problems of the functioning of ration shops?
[question] Question. What are the problems of the functioning of ration shops? [/question] [solution] Solution: The public distribution system (PDS) is the most important step taken by the Indian government towards ensuring food security. However, there have been several problems related to the functioning of ration shops. The food grains supplied by the ration shops are not enough to meet the consumption needs of the poor. As a result, they have to depend on markets instead. The average all-Ind...
Read More →What causes winds?
[question] Question. What causes winds? [/question] [solution] Solution: An uneven heating of the Earth's surface causes winds. On being heated, air becomes lighter and rises up. As a result, a region of low pressure is created. Then, air from a high pressure region moves to a low pressure region, causing wind. [/solution]...
Read More →How would flexibility in labour laws help companies?
[question] Question. How would flexibility in labour laws help companies? [/question] [solution] Solution: Flexibility in labour laws will help companies in being competitive and progressive. By easing up on labour laws, company heads can negotiate wages and terminate employment, depending on market conditions. This will lead to an increase in the company’s competitiveness. [/solution]...
Read More →How does the atmosphere act as a blanket ?
[question] Question. How does the atmosphere act as a blanket ? [/question] [solution] Solution: The atmosphere acts as a blanket by performing the following functions: (a) It keeps the average temperature of the Earth fairly constant during day time and even during the course of whole year. (b) It prevents a sudden increase in the temperature during day time. (c) It slows down the escape of heat from the surface of the Earth into outer space during night time. [/solution]...
Read More →A new unit of length is chosen such that the speed of light in vacuum is unity.
[question] Question. A new unit of length is chosen such that the speed of light in vacuum is unity. What is the distance between the Sun and the Earth in terms of the new unit if light takes 8 min and 20 s to cover this distance? [/question] [solution] solution: Distance between the Sun and the Earth: = Speed of light × Time taken by light to cover the distance Given that in the new unit, speed of light = 1 unit Time taken, $t=8 \mathrm{~min} 20 \mathrm{~s}=500 \mathrm{~s}$ ∴Distance between th...
Read More →Write notes on:
[question] Question. Write notes on: (a) Minimum support price (b) Buffer stock (c) Issue price (d) Fair-price shops [/question] [solution] Solution: (a) Minimum support price − It is the pre-announced price at which the government purchases food grains from the farmers in order to create a buffer stock. The minimum support price is declared by the government every year before the growing season. This provides incentives to the farmers for raising the production of the crops. The rising minimum ...
Read More →How is our atmosphere different from the atmospheres
[question] Question. How is our atmosphere different from the atmospheres on Venus and Mars? [/question] [solution] Solution: Earth's atmosphere is different from those of Venus and Mars. This difference lies essentially in their compositions. Earth's atmosphere is a mixture of nitrogen (79%), oxygen (20%), and a small fraction of carbon dioxide, water vapours and other gases. This makes the existence of life possible on Earth. However, the atmospheres on Venus and Mars mainly consist of carbon ...
Read More →Explain this statement clearly:
[question] Question. Explain this statement clearly: “To call a dimensional quantity ‘large’ or ‘small’ is meaningless without specifying a standard for comparison”. In view of this, reframe the following statements wherever necessary: (a) atoms are very small objects (b) a jet plane moves with great speed (c) the mass of Jupiter is very large (d) the air inside this room contains a large number of molecules (e) a proton is much more massive than an electron (f) the speed of sound is much smalle...
Read More →Why is a buffer stock created by the government?
[question] Question. Why is a buffer stock created by the government? [/question] [solution] Solution: A buffer stock of food grains is created by the government so as to distribute the procured food grains in the food-deficit areas and among the poorer strata of society at a price lower than the market price. A buffer stock helps resolve the problem of shortage of food during adverse weather conditions or during periods of calamity. [/solution]...
Read More →What was the reason for putting barriers to foreign trade and foreign investment by the Indian government?
[question] Question. What was the reason for putting barriers to foreign trade and foreign investment by the Indian government? Why did it wish to remove these barriers? [/question] [solution] Solution: Barriers to foreign trade and foreign investment were put by the Indian government to protect domestic producers from foreign competition, especially when industries had just begun to come up in the 1950s and 1960s. At this time, competition from imports would have been a death blow to growing in...
Read More →What has our government done to provide food security to the poor?
[question] Question. What has our government done to provide food security to the poor? Discuss any two schemes launched by the government? [/question] [solution] Solution: The government has ensured the availability of food grains with the help of a carefully-designed food-security system. This system involves the maintenance of a buffer stock of food grains, and the distribution of this food among the poorer sections of the society with the help of a public distribution system. The government ...
Read More →Under which of the following conditions are you most likely to fall sick?
[question] Question. Under which of the following conditions are you most likely to fall sick? (a) When you are taking examinations. (b) When you have travelled by bus and train for two days. (c) When your friend is suffering from measles. Why? [question] [solution] Solution: In condition (c), Chances of falling sick are maximum. Measles is an infectious viral disease of young children which spreads through nasal or throat discharge. In contact of a friend suffering from measles can cause you si...
Read More →Differentiate between seasonal hunger and chronic hunger.
[question] Question. Differentiate between seasonal hunger and chronic hunger. [/question] [solution] Solution: Seasonal hunger is related to cycles of food growing and harvesting. This is prevalent in rural areas because of the seasonal nature of agricultural activities, and in urban areas because of the casual labour (e.g., there is less work for casual construction labour during the rainy season). This type of hunger exists when a person is unable to get work for the entire year. Chronic hung...
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