A. 10
B. 20
C. 40
D. 80
Related Mcqs:
- Ringelmann chart is used for the evaluation of _____________ pollution?
A. Air
B. Water
C. Noise
D. Radioactive - Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air’s water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes_________________?
A. Poor visibility due to sky darkening
B. Irritation in eyes
C. Respiratory trouble
D. All A., B. and C. - Black smoke coming out of the chimney of a furnace is an indication of the use of ______________ in the furnace?
A. Low amount of excess combustion air
B. Large quantity of excess combustion air
C. Hydrocarbon fuel
D. Pulverised coal as fuel - Noise level audible to audience sitting in the 5th row from the stage during a large orchestra show corresponds to about _______________ decibels?
A. 105
B. 135
C. 160
D. 185 - White smoke coming out of the chimney of a furnace indicates the use of_________________?
A. Low excess air
B. Very high excess air
C. Gaseous fuel in the furnace
D. Liquid fuel in the furnace - Smoke is produced due to__________________?
A. Insufficient supply of combustion air and insufficient time for combustion
B. Poor quality of fuel and improper mixing of fuel & combustion air
C. Poor design & overloading of furnace
D. All A., B. and C. - Noise level heard inside a bus in busy city traffic or inside a sub-way train corresponds to about ______________ decibels?
A. 75
B. 95
C. 120
D. 140 - Shouting by a man at his full voice corresponds to a voice level of about _____________ decibels?
A. 25
B. 50
C. 80
D. 120 - Sound produced by an automobile horn heard at a distance of 1.5 metres corresponds to about ______________ decibels?
A. 90
B. 120
C. 150
D. 180 - Acute danger to human life (i.e. death) exists, if the concentration of CO2 in atmospheric air exceeds ______________ percent (by volume)?
A. 1
B. 3
C. 7
D. 20
