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This section includes 180 Mcqs, each offering curated multiple-choice questions to sharpen your Environmental Engineering knowledge and support exam preparation. Choose a topic below to get started.
101. |
Which of the following is correctly paired in the following figure? |
A. | C – Impeller |
B. | D – Outlet |
C. | F – Deflecting wall |
D. | E – Impeller |
Answer» E. | |
102. |
What will be the surface area of the basin for a flow of 2*10⁶ litre per day having a surface loading rate 10,000 litre/day/m²? |
A. | 100 |
B. | 200 |
C. | 300 |
D. | 400 |
Answer» C. 300 | |
103. |
The design value of surface loading for horizontal flow circular sedimentation is _______ |
A. | 30-40m³/m²/d |
B. | 20-30m³/m²/d |
C. | 10-20m³/m²/d |
D. | 50-100m³/m²/d |
Answer» B. 20-30m³/m²/d | |
104. |
Settling tank efficiency is reduced by _______i. Eddy currentii. Surface currentiii. Density current |
A. | i, ii |
B. | i, ii, iii |
C. | ii, iii |
D. | i, iii |
Answer» C. ii, iii | |
105. |
1cm per second settling velocity corresponds to a surface loading of ______ litre per day per m². |
A. | 36000 |
B. | 864000 |
C. | 24000 |
D. | 6000 |
Answer» C. 24000 | |
106. |
The thickness of Anthracite used in dual media filter is __________ |
A. | 10-20cm |
B. | 20-30cm |
C. | 30-40cm |
D. | 40-50cm |
Answer» D. 40-50cm | |
107. |
The chemical composition of Alum is _____________ |
A. | Al₂ (SO₄)₃.18H₂O |
B. | Al₂ (SO₄)₂.18H₂O |
C. | Al₃ (SO₄)₂.18H₂O |
D. | Al₄ (SO₄)₃.18H₂O |
Answer» B. Al₂ (SO₄)₂.18H₂O | |
108. |
The chemical compound which is insoluble in water, formed when alum is added to water is _____________ |
A. | Al (OH)₃ |
B. | CaSO₄ |
C. | CO₂ |
D. | Ca (OH)₃ |
Answer» B. CaSO₄ | |
109. |
What is formed when coagulant is added to water? |
A. | Scum |
B. | Soap |
C. | Bubbles |
D. | Floc |
Answer» E. | |
110. |
Settling velocity of a spherical body in a viscous fluid is given by ___________ |
A. | Reynolds law |
B. | Newton’s law |
C. | Stokes law |
D. | Charles law |
Answer» D. Charles law | |
111. |
The time period for which the water is stored in a sedimentation tank is called _____ |
A. | Time of flow |
B. | Frequency of flow |
C. | Settling time |
D. | Detention period |
Answer» E. | |
112. |
What is the settling velocity of the particle if its diameter is 2 * 10⁻³cm. Given G=2.65, viscosity v=8 * 10⁻³cm²/Sec? |
A. | 0.01cm/Sec |
B. | 0.13cm/Sec |
C. | 0.24cm/Sec |
D. | 0.36cm/Sec |
Answer» C. 0.24cm/Sec | |
113. |
The settling velocity of spherical particle is given by ____________ |
A. | Darcy Weisbach equation |
B. | Hazen and William equation |
C. | Stokes equation |
D. | Bernoulli’s equation |
Answer» D. Bernoulli’s equation | |
114. |
The deviation from the ideal flow of wastewater in the sedimentation tank causes ____________ |
A. | Whirlpool |
B. | Increase in tank efficiency |
C. | Short circuiting |
D. | Coagulation |
Answer» D. Coagulation | |
115. |
____ represents the size of sand particle such that 10% of particles are finer than this size. |
A. | D₀ꓸ₁ |
B. | D₁ |
C. | D₁₀ |
D. | D₁₀₀ |
Answer» D. D₁₀₀ | |
116. |
What is the effective size of Anthracite when used as a filter material? |
A. | 0.1-0.2mm |
B. | 0.2-0.4mm |
C. | 0.4-0.6mm |
D. | 0.7-0.75mm |
Answer» E. | |
117. |
The diameter of the vertical type pressure filter is __________ |
A. | 2-2.5 m |
B. | 1 m |
C. | 5 m |
D. | 10 m |
Answer» B. 1 m | |
118. |
Which of the following is the expression of the Carmen equation where symbols have their usual meanings? |
A. | hf = f* (L/(s *d)) * ((1-e)/e³) * (v²/g) |
B. | hf = f* (L/(s *d)) * ((1-e)/e³) * (v/g) |
C. | hf = f* (L/(s *d)) * ((1-e)/e) * (v²/g) |
D. | hf = f* (L/(s *d)) * ((1-e)/e²) * (v²/g) |
Answer» B. hf = f* (L/(s *d)) * ((1-e)/e³) * (v/g) | |
119. |
The sedimentation basin should be made as deep as possible. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» C. May be True or False | |
120. |
The slow sand filter is designed for _____________ |
A. | Maximum daily demand |
B. | Maximum yearly demand |
C. | Average daily demand |
D. | Maximum weekly demand |
Answer» B. Maximum yearly demand | |
121. |
Which device is used to supply air for the agitation of sand grains during washing of filters? |
A. | Rate control device |
B. | Tube settlers |
C. | Air compressors |
D. | Flocculator |
Answer» D. Flocculator | |
122. |
_______ type of trouble in filter is caused by the released of dissolved air and gases from water. |
A. | Air binding |
B. | Clogging |
C. | Mud balls |
D. | Jetting |
Answer» B. Clogging | |
123. |
What is the frequency of cleaning of a slow sand filter? |
A. | 1 week |
B. | 1-3 months |
C. | 2-3 days |
D. | 2-3 weeks |
Answer» C. 2-3 days | |
124. |
_______ is formed when alum is added to sewage. |
A. | Acid |
B. | Floc |
C. | Salt |
D. | Base |
Answer» C. Salt | |
125. |
______ are formed in filters due to insufficient washing of sand grains. |
A. | Sand boils |
B. | Mud balls |
C. | Clogging |
D. | Bubbles |
Answer» C. Clogging | |
126. |
Range of Displacement efficiency in the plain sedimentation tank is ___________ |
A. | 0.25-0.5 |
B. | 0.1-0.2 |
C. | 0.5-0.8 |
D. | 0.3-0.6 |
Answer» B. 0.1-0.2 | |
127. |
The quantity of water flowing per hour per unit horizontal area is called ________ |
A. | Detention time |
B. | Flowing through period |
C. | Displacement time |
D. | Overflow rate |
Answer» E. | |
128. |
The average time required by water to pass through the settling tank is called _______ |
A. | Detention time |
B. | Flowing through period |
C. | Time of flow |
D. | Mean time |
Answer» C. Time of flow | |
129. |
Which of the following represents the correct relation between displacement velocity and diameter of the particle? |
A. | v1 = (8Bg (G-1) d/f)^1/2 |
B. | v1 = (8Bg (G-1) d2/f)² |
C. | v1 = (8Bg (G-1) d/f) |
D. | v1 = (8Bg (G-1) d/f)² |
Answer» B. v1 = (8Bg (G-1) d2/f)² | |
130. |
The detention period of a rectangular tank is given by _______ |
A. | t0 = LBH/Q |
B. | t0 = LB/HQ |
C. | t0 = Q/LBH |
D. | t0 = HQ/LB |
Answer» B. t0 = LB/HQ | |
131. |
Consider the following statement regarding the depth of sand of the rapid gravity filter?i. It should be checked against breakage of flocii. The sand depth should lie between 100-200cmiii. The floc should be attached through the sand bedWhich of the above statement is/are correct? |
A. | Only i |
B. | i, ii |
C. | ii, iii |
D. | Only ii |
Answer» B. i, ii | |
132. |
The area of the filter is 1500. What is the number of beds to be provided? |
A. | 1 |
B. | 2 |
C. | 3 |
D. | 6 |
Answer» C. 3 | |
133. |
Schmutzdecke acts as an extremely fine meshed straining mat. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» B. False | |
134. |
What is the normal value of the detention period adopted in a flocculator for design purpose? |
A. | 30min |
B. | 60min |
C. | 90min |
D. | 100min |
Answer» B. 60min | |
135. |
In which type of settling, sedimentation of discrete particles takes place? |
A. | Zone settling |
B. | Compression settling |
C. | Hindered settling |
D. | Discrete settling |
Answer» E. | |
136. |
In which action of filtration, colloidal particles are removed? |
A. | Mechanical Straining |
B. | Sedimentation |
C. | Biological mechanism |
D. | Electrolytic action |
Answer» C. Biological mechanism | |
137. |
When the loss of the head exceeds the static head, the head becomes _____ |
A. | Positive |
B. | Negative |
C. | Constant |
D. | Zero |
Answer» C. Constant | |
138. |
The finer the suspended impurities to be removed ___________ |
A. | Larger will be the sand size |
B. | Smaller will be the sand size |
C. | Smaller will be the surface area of sand grains |
D. | Narrow will be the sand depth of the bed |
Answer» C. Smaller will be the surface area of sand grains | |
139. |
What is the settling velocity of the particle in the wastewater if its diameter is 2 * 10⁻³ cm. Given G=2.65, viscosity v=8 * 10⁻³ cm²/Sec? |
A. | 0.01cm/Sec |
B. | 0.13cm/Sec |
C. | 0.24cm/Sec |
D. | 0.36cm/Sec |
Answer» C. 0.24cm/Sec | |
140. |
Rapid sand filters are very efficient in removal of color. |
A. | True |
B. | False |
C. | May be True or False |
D. | Can't say |
Answer» B. False | |
141. |
The thickness of the base material of a rapid sand filter on which filter media are supported is __________ |
A. | 45-60cm |
B. | 20-80cm |
C. | 30-75cm |
D. | 10-30cm |
Answer» B. 20-80cm | |
142. |
Detention time for a circular tank is given by _______ |
A. | t = D (D + 0.785H) /Q |
B. | t = D (0.1D + 0.785H) /Q |
C. | t = D2 (0.01D + 0.785H) |
D. | t = D2 (0.01D + 0.785H) /Q |
Answer» E. | |
143. |
In which type of filtration problem, layers of gravel are displaced? |
A. | Clogging |
B. | Air binding |
C. | Sand incrustation |
D. | Sand leakage |
Answer» E. | |
144. |
When the Reynolds number is greater than 1.9 but less than 500, the coefficient of drag CD is? |
A. | CD = 24/R |
B. | CD = R/24 |
C. | CD = 18.5/R⁰·⁶ |
D. | CD = R⁰·⁶/18.5 |
Answer» D. CD = R⁰·⁶/18.5 | |
145. |
The chemical composition of Chlorinated Copperas is __________ |
A. | Fe₂ (SO₄)₃ + FeCl₃ |
B. | FeSO₄.9H₂O |
C. | FeSO₄.18H₂O |
D. | Fe₂ (SO₄)₃ |
Answer» B. FeSO₄.9H₂O | |
146. |
Alum is effective when pH of water is between ____ |
A. | 8-10 |
B. | 6-8 |
C. | 6.5-8.5 |
D. | 7-9 |
Answer» D. 7-9 | |
147. |
Why Alum is preferred over other coagulants? |
A. | It is easy to dewater the sludge formed |
B. | It imparts corrosiveness to water |
C. | It reduces taste and odor in addition to turbidity |
D. | The time required for floc formation is less |
Answer» D. The time required for floc formation is less | |
148. |
Which gas is released when alum is added to water? |
A. | Al (OH)₃ |
B. | CaSO₄ |
C. | CO₂ |
D. | Ca (OH)₃ |
Answer» D. Ca (OH)₃ | |
149. |
What indicates the permanent hardness when alum is added to water? |
A. | Al (OH)₃ |
B. | CaSO₄ |
C. | CO₂ |
D. | Ca (OH)₃ |
Answer» C. CO₂ | |
150. |
The rate of filtration of pressure filtration is ______ l/m²/hour. |
A. | 1000-5000 |
B. | 5000-10000 |
C. | 6000-8000 |
D. | 6000-15000 |
Answer» E. | |