Environmental Engineering – Multiple Choice Questions (MCQs)

1. 73. Which type of pipe is commonly used for water distribution mains due to its durability and resistance to corrosion?

   • A. PVC pipe
   • B. Cast iron pipe
   • C. Galvanized iron pipe
   • D. Asbestos cement pipe

2. 74. What is "Water Hammer" in pipelines?

   • A. A tool for repairing pipes
   • B. A sudden increase in pressure in a pipeline caused by an abrupt change in flow velocity
   • C. A type of water pump
   • D. A method of cleaning pipes

3. 75. The "design period" for water supply projects is typically:

   • A. 5-10 years
   • B. 15-30 years
   • C. 50-100 years
   • D. More than 100 years

4. 76. What is the "unit demand" for water supply?

   • A. Total water consumed by a city
   • B. Water consumed per person per day
   • C. Water lost due to leakage
   • D. Water used by industries

5. 77. What is the primary method of wastewater collection in urban areas?

   • A. Open channels
   • B. Canals
   • C. Sewerage systems
   • D. Rivers

6. 78. The minimum velocity required in a sewer pipe to prevent solids from settling is called:

   • A. Critical velocity
   • B. Self-cleansing velocity
   • C. Design velocity
   • D. Maximum velocity

7. 79. What is a "manhole" in a sewerage system?

   • A. A place for garbage disposal
   • B. An access point for inspection and maintenance of sewers
   • C. A wastewater treatment unit
   • D. A pumping station

8. 80. The slope of a sewer pipe is designed to:

   • A. Increase pumping requirements
   • B. Ensure self-cleansing velocity and proper flow
   • C. Prevent blockages due to high velocity
   • D. Reduce construction cost

9. 81. What is "Combined Sewer System"?

   • A. A system that carries only stormwater
   • B. A system that carries only domestic sewage
   • C. A system that carries both domestic sewage and stormwater
   • D. A system that carries industrial waste only

10. 82. What is "Separate Sewer System"?

    • A. A system that carries both domestic sewage and stormwater
    • B. A system where domestic sewage and stormwater are collected and transported in separate pipes
    • C. A system for industrial waste
    • D. A system for agricultural runoff

11. 83. The primary advantage of a separate sewer system is:

    • A. Lower initial cost
    • B. Reduced volume of wastewater to be treated
    • C. Higher maintenance
    • D. Increased risk of overflow

12. 84. What is "Biochemical Oxygen Demand (BOD5)"?

    • A. Oxygen consumed by chemical reactions in 5 days
    • B. Oxygen consumed by microorganisms for decomposition of organic matter in 5 days at 20°C
    • C. Oxygen produced by plants in 5 days
    • D. Oxygen saturation level in 5 days