Environmental Engineering

111.Maximum permissible limit of mercury in human blood is _________ micrograms/100 c.c.

1. 1
2. 7
3. 19
4. 82

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112.Maximum permissible residual chlorine in treated water should be _________ mg/litre.

1. 0.001 to 0.01
2. 0.2 to 0.3
3. 2 to 3
4. 5 to 10

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113.Maximum permissible turbidity in potable water is _________ ppm.

1. 1
2. 10
3. 250
4. 1000

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114.Methyl isocyanate (MIC) gas (TLV <1 ppm), which caused Bhopal gas tragedy in 1984 falls under the category of _________ toxic gas.

1. Moderately
2. Highly
3. Extremely
4. Very extremely

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115.Moist atmospheric air at high temperature (e.g., in summer) having high concentration of sulphur dioxide causes

1. Fading of dyes on textiles
2. Corrosion, tarnishing&soiling of metals
3. Reduced strength of textiles
4. All (A), (B) and (C)

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116.Most efficient and suitable dust removal equipment for removal of fly-ash from flue gas in a thermal power plant is the

1. Gravity settling chamber
2. Cyclone separator
3. Electrostatic precipitator
4. Bag filter

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117.Most of the atmospheric air pollutants are present in large quantity in

1. Stratosphere
2. Thermosphere
3. Troposphere
4. Mesosphere

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118.Nitrogen oxides (NOx) is not produced in the _________ industry.

1. Nitric acid making
2. Nitrogenous fertiliser
3. Detergent
4. Any of these

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119.Noise emitted by a ventilation fan at a distance of 3 metres is about _________ decibels.

1. 85
2. 105
3. 125
4. 145

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120.Noise level audible to audience sitting in the 5th row from the stage during a large orchestra show corresponds to about _________ decibels.

1. 105
2. 135
3. 160
4. 185

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