Browsing category
Maximum allowable noise exposure limits for a man working for 8 hours a day in a noisy chemical plant is about ______________ decibels? A. 20 B. 60C. 90 D. 120
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 furnaceD. All A., B. and C.
World environment day is observed every year on the 5th of___________________? A. June B. December C. July D. September
Foul odour and bad taste of water is removed by treating with__________________? A. Alum B. Bleaching powderC. Activated carbon D. Copper sulphate
Pick out the wrong statement. A. Caustic embrittlement of boiler’s metallic parts is caused by high concentration of caustic soda in boiler feed water___________________? B. Cooling and freezing of water kills the bacteria present in it C. With increasing boiler operating pressure of steam, the maximum allowable concentration of silica in feed water goes on…
Presence of a certain minimum quantity of fluorine is desirable in potable water to prevent___________________? A. Dental cavities B. Scale formation C. Water-borne disease D. Corrosion
TLV of mercury in potable (drinking) water is about ______________ ppm? A. 0.001 B. 0.1 C. 1 D. 5
Presence of iron and manganese in water causes___________________? A. Reduction in its dissolved oxygen contentB. Discoloration of bathroom fixtures C. Temporary hardness D. None of these
Presence of soluble organics in polluted water causes_________________? A. Undesirable plants growthB. Depletion of oxygen C. Fire hazards D. Explosion hazards
Persons working in cement plants and limestone quarries are more prone to disease like__________________? A. Cancer B. AsthmaC. Silicosis D. Fluorosis (bone disease)