11) A commonly used handpump is the
a) centrifugal pump
b) reciprocating pump
c) rotary pump
d) axial flow pump
12) Product of H+ ions and OH– ions in water is equal to
(a) zero
(b) 10–3
(c) 10–7
(d) 10–14
13) The maximum allowable concentration of iron in water is
a) 1.0 ppm
b) 0.05 ppm
c) 0.3 ppm
d) 0.03 ppm
14) Which one of the following is not bacteria from sewage and animal excrement?
(a) cocci
(b) coli-aerogenes group
(c) Clostridium welchii
(d) faecal streptococci
15) What is the most common cause of acidity in water ?
a) Carbon monoxide
b) Nitrogen
c) Hydrogen
d) Carbon dioxide
16) Alum is found to be effective when pH of water ranges between
(a) 2.5 to 4.5
(b) 4.5 to 6.5
(c) 6.5 to 8.5
(d) 8.5 to 10.5
17) Which of the following compounds is used in algae control ?
a) ferric sulphate
b) calcium chloride
c) copper sulphate
d) ferric chloride
18) Uniformity coefficient of sand for slow sand filters shall be
(a) 1 to 3
(b) 3 to 5
(c) 5 to 7
(d) 7 to 10
19) At break point chlorination the residual chlorine is
a) zero
b) minimum
c) maximum
d) reappears
20) Hydrants are provided at all junctions of roads and at ______ a port along the road.
(a) 100 – 130 m
(b) 200 – 300 m
(c) 300 – 400 m
(d) 400 – 500 m