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Tag Archives: NCERT Class 8 Science Chapter

NCERT 8th Class (CBSE) Science: Pollution of Water and Air


Question: What harm can dumping of untreated sewage into a river cause? Answer: Untreated sewage from homes is often disposed off into rivers. These wastes contain many harmful microorganisms – bacteria, viruses, fungi and parasites that cause diseases such as diarrhoea, dysentery, cholera, typhoid and jaundice. Question: Why is hot water …

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NCERT 8th Class (CBSE) Science: Chemical Effects of Electric Current


Question: What is electric current? Answer: The flow of electrons constitutes an electric current. Question: How is electronic current different from conventional current? Answer: The flow of electronic current is from negative to positive whereas the flow of conventional current is from positive to negative. Question: Differentiate between conductors and insulators. Answer: Difference is as …

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NCERT 8th Class (CBSE) Science: Sound


Question: How is sound produced? Answer: Sound is produced by rapid to-and-fro movements called vibrations. Question: Distinguish between infrasonic and ultrasonic. Answer: Difference is as follows: Question: What do you mean by time period of a vibrating object? Answer: The time taken for one complete vibration or oscillation is called its time period. Question:What is …

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NCERT 8th Class (CBSE) Science: Conservation of Plants and Animals

Animals – Habitat and Adoption

Question: What is biodiversity? Answer: Biodiversity is the variety of plants, animals and microorganisms generally found in an area. Question: What do you mean by flora and fauna? Answer: Flora: Species of all plants found in a particular area is known as flora of that area. Fauna: Species of all animals found in …

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NCERT 8th Class (CBSE) Science: Combustion and Flame


Question: What is combustion? Answer: The process of burning of substances in air or oxygen with the evolution of heat and light is known as combustion. Question: Distinguish between combustible and non-combustible substances, giving three examples of each. Answer:  Question: Why is it more difficult to burn some combustible substances than others? Answer: Different substances …

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