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MCQ
16301. Main element of biogas is
CO2
Cow dung
Water
CH4
ব্যাখ্যা: Typical composition of biogas- Methane 50-80% Carbon dioxide 25-50% Nitrogen 0-10% Hydrogen 0-1% Hydrogen sulphide 0-3% So the main element of biogas is Methane
16302. The most important source of water for public water supply is-
lake
pond
river
sea
16303. The water obtained from a lake is known as surface water.
Agree
Disagree
16304. The water obtained from is generally known as sub-surface water---
rain
reservoirs
rivers
artesian wells
16305. The presence of sodium chloride in water-
stops epidemic
increases hardness of water
causes bad taste
softens the water
16306. Absolute zero temperature = ?
0°C
273°C
-273°C
None
ব্যাখ্যা: The coldest possible temperature is called absolute zero temperature. This temperature is 0°K or-273°C
16307. The presence of bacteria in water causes-
hardness
diseases
alkalinity
bad taste
16308. The diameter of a domestic sewer pipe laid at gradient 1 in 100 is recommended ------
100 mm
200mm
150mm
175mm
ব্যাখ্যা: All sanitary sewage of domestic and other water borne wastes shall be collected and conveyed in a sanitary sewer pipe. These recommended gradients are 1 in 30 (75mun pipe), 1 in 40 (100 mm pipe) and 1 in 100 (150 mm pipe).
16309. The design period for a water supply project is taken as-
5 to 10 years
15 to 20 years
10 to 15 years
20 to 30 years
16310. What do you mean by BOD?
Best organized demand
Biochemical oxygen demand
Before oxidation damage
Bacteria of damage
ব্যাখ্যা: The full name of BOD is Biochemical Oxygen Demand. BOD refers to the amount of dissolved oxygen (DO) that arrobic organism need in order to break down organic naterial in water over time.
16311. Arsenic contamination has primarily affected-
the deep aquifer
the river
the shallow aquifer
none
ব্যাখ্যা: Arsenic contamination has primarity affected the shallow aquifer and Arsenic free from deep aquifer.
16312. The quality of tube well water is ---as compaired to surface water
good
poor
16313. The maximum permissible limit for iron in drinking water is-
0.1 mg/L
0.3-1 mg/L
2-2.5 mg/L
5 mg/L
16314. The groundwater is generally free from impurities.
suspended
dissolved
16315. The water bearing strata i.e. layers of sand, gravel etc. is called-
an aquifer
zone of saturation
an aquifuge
an aquiclude
16316. Suspended impurities consist of-
iron
bacteria
chlorine
all of these
16317. Absolute pure water is good for health.
right
wrong
16318. Which of the following protects penstock due to sudden variation of flow or velocity of water?
Anchors
Trash rack
Forebays
Surge tank
ব্যাখ্যা: Surge tank connected to a pipe carrying a liquid and intended to neutralized sudden change of pressure in the flow by filing when the pressure increases and emptying when it drops.
16319. What is the example of metamorphic rock?
granite
genesis
marble
all of these
ব্যাখ্যা: A marble is an example of a metamorphic rock It is composed of recrystallized carbonated minerals, most commonly calcite or dolomite.
16320. The open wells or dug wells are also known as-
shallow wells
percolation wells
draw wells
all of these