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