251. TLV of NO2 & NO exposure for the human being is 5 & 25 ppm respectively. Prolonged exposure of human being to NO2 causes
252. Sulphur dioxide present in the industrial chimney exhaust gases causes
253. A man exposed to excessive noise level in the working environment may suffer from
254. Which of the following is a secondary air pollutant ?
255. Presence of __________ bacteria in water causes disease like typhoid.
256. CFC (chloro fluoro carbon) is very highly reactive in causing depletion of ozone layer in the atmosphere. Each atom of chlorine liberated from CFC is capable of decomposing __________ molecules of ozones.
257. Green house gases blanket/block the infrared radiation from earth's surface to the atmosphere leading to its progressive warming up. Which of the following gases does not exhibit green house effect ?
258. A 'body' which allows the short wavelength incoming solar radiation to enter in, but does not allow long wave length outgoing infra red radiation to escape out is called the
259. Fresh domestic sewage is __________ in color.
260. The common pollutant generated in chlor-alkali industry and battery manufacture is
261. During sewage treatment, the sewage is subjected to __________ treatment in Imhoff tank.
262. Black smoke coming out of the chimney of a furnace is an indication of the use of __________ in the furnace.
263. __________ content of the phosphate rock is the pollutant of primary interest in a phos-phatic fertiliser plant.
264. Beyond what concentration of H2S in air, acute danger to human life exists ?
265. Reingleman chart is used for the evaluation of __________ pollution.
266. There are five concentric layers within the atmosphere which is differentiated on the basis of temperature. The atmospheric layer which lies close to the earth's surface in which human being along with other organisms live is called troposphere. The rate at which air temperature in the troposphere gradually decreases with height is about __________ °C/km.
267. Brown spots in fabrics will be caused by washing with water containing large amount of .
268. Maximum permissible concentration (i.e. TLV) of DDT in public water supply system is __________ micro gram (μ g)/litre.
269. 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
270. Deaeration of high pressure boiler feed water is done to reduce
271. Exposure to SO2 containing chimney gases results in the
272. The detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of __________ of water.
273. Hydrogen ion concentration in distilled water is
274. Out of the following, TLV of __________ is maximum (about 500 ppm).
275. Which of the following plants does not emit appreciable amount of SO2 in atmosphere ?