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