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In which of the following conditions, the distance between the molecules of hydrogen gas would increase? (i) Increasing pressure on hydrogen contained in a closed container (ii) Some hydrogen gas leaking out of the container (iii) Increasing the volume of the container of hydrogen gas (iv) Adding more hydrogen gas to the container without increasing the volume of the container (a) (i) and (iii) (b) (i) and (iv) (c) (ii) and (iii) (d) (ii) and (iv)

C) (ii) and (iii) Universal gas law states that PV=nRT Pressure is directly proportional to temperature and indirectly proportional to the volume... View Article

Read the paragraph and answer the questions following it. Water is essential for life. Without water, there would be no life. We usually take water as granted for its purity, but we must ensure the quality of water. Pollution of water originates from human activities. Through different paths, pollution reaches to groundwater. Easily identified source or place of pollution is called a point source, e.g.– municipal and industrial discharge pipes, where pollutants enter the water source. Non–point sources of pollution are those where a source of pollution can not be easily identified, e.g.– agricultural runoff, acid rain etc. 1) How do you classify the various sources of water pollution? 2) What are the point sources of water pollution? 3) Name any two non-point sources of water pollution?

(a) Various sources of water pollution are classified as point sources and non-point sources. (b) The sources or places of pollution which are... View Article

Some words (underlined) in the following sentences are jumbled up. Write them in their correct form. (a) Seldie is a combustible substance. (b) Slags is a non-combustible material. (c) Chittsmack does not burn by itself. (d) Some substances on combustion produce thea and mafel. (e) The amount of heat energy produced on complete combustion of 1 kg of a fuel is called its Aricolci uelav.

(a) Diesel is a combustible substance. When a substance ;can burn in air and produce heat and light is known as a combustible substance. (b)... View Article

Find out the correct sentence 1) Hybridisation means crossing between genetically dissimilar plants 2) Cross between two varieties is called as inter specific hybridisation 3) Introducing genes of desired character into a plant gives genetically modified crop 4) Cross between plants of two species is called as inter varietal hybridisation (a) (i) and (iii) (b) (ii) and (iv) (c) (ii) and (iii) (d) (iii) and (iv)

A. (i) and (iii) The cross performed between two plants belonging to different species (having different characters) is referred to as... View Article