Q1: Pick up the correct statement from the following :

ANS:D - The larger the sewer in size, deposition will take place.

The larger the sewer in size, deposition will take place" is generally incorrect or at least misleading as a standalone statement. However, under certain conditions, it can be partially true. In sewer systems, deposition refers to the settling of solids within the sewer pipes. When the flow velocity of sewage decreases significantly, either due to a reduction in slope or a sudden increase in pipe size, sedimentation of solids may occur. This sedimentation can lead to the deposition of solids such as sand, grit, and organic matter onto the bottom of the sewer pipe. While it's true that larger sewer pipes tend to have lower flow velocities compared to smaller pipes for the same flow rate, the likelihood of deposition occurring solely due to the size of the sewer is not accurate. Other factors such as flow velocity, flow regime, pipe slope, and characteristics of the wastewater all play crucial roles in determining whether deposition will occur. In some cases, larger sewer pipes may be designed to minimize flow velocities and prevent erosion, but they are often equipped with features like scouring jets or other mechanisms to prevent deposition. Proper sewer design, maintenance, and operational practices are essential to minimize the risk of deposition in sewer systems, regardless of pipe size.