Ncert- science – class 7- Chapter 13 – Wastewater Story 1 Welcome to your Ncert- science – class 7- Chapter 13 – Wastewater Story 1 1. Addition of harmful substance in water leads to Microbial growth Algal bloom High oxygen demand Water pollution None 2. Water polluted by various human activities causes a number of water borne diseases. Which of the following is not a water borne disease? Dysentry Typhoid Cholera Asthma None 3. Which of the following is biodegradable? Plastic bottle Aluminium Aluminium foil Orange peels None 4. The system of a network of pipes used for taking away wastewater from homes or public buildings to the treatment plant is known as sewers treatment plant. sewerage transport system. None 5. Biodegradable waste Does not decompose Accumulates in environment Decomposes in nature by microbes Enters the food chains then causes bio magnification None 6. An example of source reduction of waste is Backyard composting Making paper aero planes Burning Throwing things that are old None 7. Which of the following is wastewater? Water coming out of a shower. Water flowing in a river. Water trickling from a damaged tap. Water coming out of a laundry. None 8. Bacteria that decompose organic wastes are called Anaerobic bacteria Lactobacillus bacteria All of these Aerobic bacteria None 9. Open drain system is a breeding place for which of the following? Organisms which cause diseases All of these Mosquitoes Flies None 10. Filtration plants uses _____ filters to remo sand paper none of these steel None 11. Pick from the following one chemical used to disinfect water Coal Washing soda Chlorine Silica None 12. Which of the following is a part of inorganic impurities of the sewage? Urea Pesticides Vegetable waste Phosphates None 13. Which among the following are ways to conserve water? Use less/limited water while bathing. Boil limited cups of water for drinking. Turn off the taps while brushing teeth. All of the above None 14. The direct discharge of pollutants into water bodies leads to Water pollution Air pollution Soil pollution All of the above None 15. In a filtration plant water is filtered using layers of clay and fine gravel. sand, fine gravel and medium gravel. sand and clay. sand and fine gravel. None 16. Bacteria that decompose organic wastes are called Aerobic bacteria Anaerobic bacteria All of these Lactobacillus bacteria None 17. Which of the following is removed when wastewater is passed through bar screens? Grit Sand Pebbels Cans None 18. Which of the following is/are products of wastewater treatment? Sludge Biogas Both biogas and sludge Aerator None 19. Which of the following is not an example of municipal solid waste? Sewage Paper Packing materials Batteries None 20. Polythene and plastics Are not harmful Degrade in the environment very easily Do not generate any bad odour Are non-biodegradable and very harmful None Time's up Please Share This Share this content Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Opens in a new window Leave a Reply Cancel replyCommentEnter your name or username to commentEnter your email address to commentEnter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.
