Question: When a liquid rotates at a constant angular velocity about a vertical axis as a rigid body, the pressure intensity varies________________?

• 1. linearly with radial distance
• 2. as the square of the radial distance
• 3. inversely as the square of the radial distance
• 4. inversely as the radial distance

Question: The point in the immersed body through which the resultant pressure of the liquid may be taken to act is known as__________________?

• 1. center of gravity
• 2. center of buoyancy
• 3. center of pressure
• 4. metacentre

Question: If the weight of a body immersed in a fluid exceeds the buoyant force, then the body will________________?

• 1. rise until its weight equals the buoyant force
• 2. tend to move downward and it may finally sink
• 3. float
• 4. none of the above

Question: A floating body is said to be in a state of stable equilibrium_________________?

• 1. when its metacentric height is zero
• 2. when the metacentre is above the centre of gravity
• 3. when the metacentre is below the centre of gravity
• 4. only when its centre of gravity is below its centre of buoyancy

Question: A vertical rectangular plane surface is submerged in water such that its top and bottom surfaces are 1.5 m and 6.0 m res-pectively below the free surface. The position of center of pressure below the free surface will be at a distance of________________?

• 1. 3.75 m
• 2. 4.0 m
• 3. 4.2m
• 4. 4.5m

Question: The process in which the chlorination is done beyond the break point is known as_________________?

• 1. prechlorination
• 2. post chlorination
• 3. super chlorination
• 4. break point chlorination

Question: Double filtration is used_______________?

• 1. to increase the filtration slow sand filters capacity of
• 2. to increase the filtration rapid sand filters capacity of
• 3. for isolated buildings like pools, hotels etc swimming
• 4. all of the above

Question: Disinfection of water results in______________?

• 1. removal of turbidity
• 2. removal of hardness
• 3. killing of disease bacteria
• 4. complete sterilisation

Question: Period of cleaning of slow sand filters is about________________?

• 1. 24 – 48 hours
• 2. 10-12 days
• 3. 2-3 months
• 4. 1-2 year

Question: Air binding phenomena in rapid sand filters occur due to_________________?

• 1. excessive negative head
• 2. mud ball formation
• 3. higher turbidity in the effluent
• 4. low temperature