CPCB Scientist B Paper  | Central Pollution Control Board Scientist B Old Paper for Chemical/ Civil/ Environmental Engineering

(Every Correct answer 1 mark, every wrong answer – 0.25 mark as a negative marking)

The head loss in turbulent flow in pipe
(a) Varies approximately as the square of the velocity
(b) Varies inversely as the square of the velocity
(c) Varies inversely as the diameter of the pipe
(d) Varies inversely as the velocity

Which of the followins is used for the measurement of discharge
(a) Pitot tube
(b) Venturi-meter
(c) Current-meter
(d) None of the above

For a given specific energy ‘E’ the critical depth ‘ye’ for a rectangular channel section is equal to
(a) 2E/3
(b) 3E/2
(c) E/2
(d) 5E/2

Electrostatic precipitators remove
(a) Particulate matter
(b) Sulphur dioxide
(c) Hydrogen Sulphide
(d) Nitric Oxide

When Environmental Lapse Rase (ELR) is more than Adiabatic Lapse Rate (ALR), then the environment is said to be
(a) Stable
(b) Unstable
(c) Neutral
(d) None of the above

Match List-I equipment with List II Pollutants
List I – (A) Electrostatic Precipitators (B) Cyclones (C) Wet scrubbers (D) Adsorbers
List II- (1) Coarse particles (2) Fine dust (3) Gas (4) Sulphur dioxide
(a) A-1, B-2, C-3, D-4
(b) A-2, B-1, C-3, D-4
(c) A-2, B-1, C-4, D-3
(d) A-1, B-2, C-4, D-3

The distribution system in water supplies is designed on the basis of
(a) Avreage daily demand
(b) Peak hourly demand
(c) Coincident draft
(d) Greater of b and c

A ranney well, largely used for apping round water for public supplies, receives ground water from
(a) Its bottom
(b) Its vertical permeable sides
(c) Radial horizontal collectors
(d) None of the above

The velocity of flow in a sedimentation tank is generally kept as
(a) 0.3 m/sec
(b) 0.3 m/minute
(c) 0.3 m/hour
(d) 0.3 m/day

Which of the following processes of softening water may require re-carbonation
(a) Lime-soda process
(b) Hydrogen/ Sodium cation exchange process
(c) Demineralization process
(d) Reverse osmosis process

In water supply, a Jar test is performed
(i) to obtain the optimal does of coagulant to be used in coaguation process
(ii) to find out the optimal time required for flocculation
(iii) to find the chlorine conent of water
The correct statements are
(a) Only (i)
(b) Only (ii)
(c) (i) and (ii)
(d) (i) and (iii)

EDTA (Ethylene diamine tetra acetic acid) solution is used to determine
(a) Dissolved oxygen in water
(b) Residual chlorine in water
(c) Hardness in water
(d) Optimal dose of coagulant

The most common cause of acidity in water is
(a) Carbon dixoide
(b) Organic acids
(c) Mineral acids
(d) Oxides of Nitrogen or sulphur

While designing sewers, the flow velocity at full design depth is generally kept at about
(a) 1.0 m/sec
(b) 0.5 m/sec
(c) 1.5 m/sec
(d) Less than 0.3 m/sec

As compared to slow sand filters, rapid sand filters give
(i) slower filtration rate
(ii) higher filtration rate
(iii) lesser efficiency in removal of bacteria
(iv) higher efficiency in removal of bacteria
Of the above statements, the correct statements are
(a) (i) and (iii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (ii) and (iv)