1. Disinfection of water results in______________?.
A. removal of turbidity
B. removal of hardness
C. killing of disease bacteria
D. complete sterilisation.
Answer = killing of disease bacteria
2. Period of cleaning of slow sand filters is about________________?.
A. 24 – 48 hours
B. 10-12 days
C. 2-3 months
D. 1-2 year.
Answer = 2-3 months
3. Air binding phenomena in rapid sand filters occur due to_________________?.
A. excessive negative head
B. mud ball formation
C. higher turbidity in the effluent
D. low temperature.
Answer = excessive negative head
4. The rate of filtration in slow sand filters in million litres per day per hectare is about_____________?.
A. 50 to 60
B. 100 to 150
C. 500 to 600
D. 1400 to 1500.
Answer = 50 to 60
5. The chemical most commonly used to increase speed of sedimentation of sewage is_______________?.
A. sulphuric acid
B. copper sulphate
C. lime
D. sodium permanganate.
Answer = lime
6. The detention period in coagulation tanks is usually kept as_______________?.
A. 1 to 2 minutes
B. 30 to 45 minutes
C. 2 to 6 hours
D. 2 to 6 days.
Answer = 2 to 6 hours
7. For a given discharge, the efficiency of sedimentation tank can be increased by______________?.
A. increasing the depth of tank
B. decreasing the depth of tank
C. increasing the surface area of tank
D. decreasing the surface area of tank.
Answer = increasing the surface area of tank
8. The settling velocity of a particle in a sedimentation tank depends on__________________?.
A. depth of tank
B. surface area of tank
C. both depth and surface area of tank
D. none of the above.
Answer = surface area of tank
9. The overflow rate for plain sedimentation tanks is about__________________?.
A. 500 to 750 litres/hour/ m2
B. 1000 to 1250 litres/hour/ m2
C. 1250 to 1500 litres/hour/m2
D. 1500 to 2000 litres/hour/m2.
Answer = 500 to 750 litres/hour/ m2
10. The settling velocity of a particle in a sedimentation tank increases if_________________?.
A. particle size is decreased
B. the surface area of tank is increased
C. the depth of tank is decreased
D. none of the above.
Answer = none of the above
11. The velocity of flow of water in a sedimentation tank is about__________________?.
A. 5 to 10 cm/sec.
B. 15 to 30 cm/sec.
C. 15 to 30 cm/minute
D. 15 to 30 cm/hour.
Answer = 15 to 30 cm/minute
12. The amount of residual chlorine left in public water supply for safety against pathogenic bacteria is about______________?.
A. 0.01 to 0.05 ppm
B. 0.05 to 0.5 ppm
C. 0.5 to 1.0 ppm
D. 1.0 to 5.0 ppm.
Answer = 0.05 to 0.5 ppm
13. Orthotolidine test is used for determination of________________?.
A. dissolved oxygen
B. residual chlorine
C. biochemical oxygen demand
D. dose of coagulant.
Answer = residual chlorine
14. On standard silica scale, the turbidity in drinking water should be limited to_______________?.
A. 10 ppm
B. 20 ppm
C. 30 ppm
D. 50 ppm.
Answer = 10 ppm
15. Which of the following values of pH represents a stronger acid?.
A. 2
B. 5
C. 7
D. 10.
Answer = 2
16. Ground water is usually free from________________?.
A. suspended impurities
B. dissolved impurities
C. both suspended and dissolved impuri¬ties
D. none of the above.
Answer = suspended impurities
17. The maximum discharge of a tube-well is about_________________?.
A. 5 litres/sec
B. 50 litres/sec
C. 500 litres/sec
D. 1000 litres/see.
Answer = 50 litres/sec
18. The phenolic compounds in public water supply should not be more than_______________?.
A. 0.1 ppm
B. 0.01 ppm
C. 0.001 ppm
D. 0.0001 ppm.
Answer = 0.001 ppm
19. Which of the following is not a water borne disease ?.
A. dysentery
B. cholera
C. typhoid
D. maleria.
Answer = maleria
20. Select the correct relationship between porosity (N), specific yield (y) and specific retention (R)________________?.
A. N = y + R
B. y = N + R
C. R = N + y
D. R > (N + y).
Answer = N = y + R
21. The suitable method of forecasting popu¬lation for a young and rapidly increasing city is_________________?.
A. arithmetical increase method
B. geometrical increase method
C. incremental increase method
D. graphical method.
Answer = geometrical increase method
22. As compared to geometrical increase method of forecasting population, arithmetical increase method gives________________?.
A. lesser value
B. higher value
C. same value
D. accurate value.
Answer = lesser value
23. If the average daily consumption of a city is 100,000 m3, the maximum daily con¬sumption on peak hourly demand will be_______________?.
A. 100000m3
B. 150000m3
C. 180000m3
D. 270000 m3.
Answer = 270000 m3
24. Which of the following causes a decrease in per capita consumption ?.
A. use of metering system
B. good quality of water
C. better standard of living of the people
D. hotter climate.
Answer = use of metering system
25. Assertion A : The consumption of water increases with increase in the distribution pressure. Reason R : Higher distribution pressure causes more loss and waste of water. Select your answer according to the coding system given below?.
A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true.
Answer = Both A and R are true and R is the correct explanation of A
26. The devices which are installed for drawing water from the sources are called______________?.
A. aquifers
B. aquiclude
C. filters
D. intakes.
Answer = intakes
27. Select the correct statement?.
A. 5 day BOD is the ultimate BOD
B. 5 day BOD is greater than 4 day BOD keeping other conditions same
C. 5 day BOD is less than 4 day BOD keeping other conditions same
D. BOD does nof depend on time.
Answer = 5 day BOD is less than 4 day BOD keeping other conditions same
28. Number of unknown internal forces in each member of a rigid jointed plane frame is_____________?.
A. 1
B. 2
C. 3
D. 6.
Answer = 3
29. Degree of kinematic indeterminacy of a pin-jointed plane frame is given by______________?.
A. 2j – r
B. j – 2r
C. 3j – r
D. 2j + r.
Answer = 2j – r
30. If in a pin-jointed plane frame (m + r) > 2j, then the frame is________________?.
A. stable and statically determinate
B. stable and statically indeterminate
C. unstable
D. none of the above where m is number of members, r is reaction components and j is number of joints.
Answer = stable and statically indeterminate
31. A rigid-jointed plane frame is stable and statically determinate if_______________?.
A. (m + r) = 2j
B. (m + r) = 3j
C. (3m + r) = 3j
D. (m + 3r) = 3j where m is number of members, r is reaction components and j is number of joints.
Answer = (3m + r) = 3j
32. The degree of static indeterminacy of a pin-jointed space frame is given by_________________?.
A. m + r – 2j
B. m + r – 3j
C. 3m + r – 3j
D. m + r + 3j.
Answer = m + r – 3j
33. The degree of kinematic indeterminacy of a pin-jointed space frame is_____________?.
A. 2j-r
B. 3j-r
C. j-2r
D. j-3r where j is number of joints and r is reaction components.
Answer = 3j-r
34. Castigliano's first theorem is applicable_______________?.
A. for statically determinate structures only
B. when the system behaves elastically
C. only when principle of superposition is valid
D. none of the above.
Answer = only when principle of superposition is valid
35. In moment distribution method, the sum of distribution factors of all the members meeting at any joint is always__________________?.
A. zero
B. less than 1
C. 1
D. greater than 1.
Answer = 1
36. In column analogy method, the area of an analogous column for a fixed beam of span L and flexural rigidity El is taken as__________________?.
A. L/EI
B. L/2EI
C. L/3EI
D. L/4EI.
Answer = L/EI
37. The deflection at any point of a perfect frame can be obtained by applying a unit load at the joint in_________________?.
A. vertical direction
B. horizontal direction
C. inclined direction
D. the direction in which the deflection is required.
Answer = the direction in which the deflection is required
38. The three moments equation is applicable only when___________________?.
A. the beam is prismatic
B. there is no settlement of supports
C. there is no discontinuity such as hinges within the span
D. the spans are equal.
Answer = there is no discontinuity such as hinges within the span
39. The Castigliano's second theorem can be used to compute deflections________________?.
A. in statically determinate structures only
B. for any type of structure
C. at the point under the load only
D. for beams and frames only.
Answer = for any type of structure
40. For a two-hinged arch, if one of the supports settles down vertically, then the horizontal thrust______________?.
A. is increased
B. is decreased
C. remains unchanged
D. becomes zero.
Answer = remains unchanged