302. Iron content more than 0.3 mg/litre
A. causes discolouration of clothes
B. causes incrustation of water mains
C. makes water pleasant to taste
D. makes water reddish.
303. The ensure proper growth of children's teeth, the quantity of flouride used in water mains, is
A. 1 mg/litre
B. 2 mg/litre
C. 3 mg/litre
D. 4 mg/litre
304. Sluice valves are fitted in a distribution system
A. along straight length of pipes at suitable intervals
B. at the junctions of the pipes
C. at the branching off points of sub-mains
D. all the above.
305. In distribution pipes, drain valves are provided at
A. lower point
B. higher point
C. junction points
D. any where.
306. In distribution pipes, air valves are provided at
A. lower points
B. junction points
C. higher points
D. any where.
307. For a city developed haphazardly, the layout of distribution pipes preferred to, is
A. ring system
B. radial system
C. grid iron system
D. dead end system.
308. In a well planned city, the layout of distribution pipes generally adopted, is
A. grid-iron system
B. interlaced system
C. reticulation system
D. all the above.
Page 44 of 53