Noise level heard at a distance of about 100 metres from a jet engine with after burner is about _____________ decibels?

Related Mcqs:

The weakest sound that can be heard by a person in a quiet environment is equivalent to ____________ decibel ?

A. 1 B. 5 C. 10 D. 50...

Noise produced by cooling fans (employed in air cooled heat exchangers or cooling tower) is mainly caused due to the turbulence created by blade passage through air. It can be reduced by use of a slower fan_________________?

A. With greater number of blades B. Of increased diameter C. Both A. & B. D. Neither A. nor B....

The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ?

A. Chlorine B. Alkalis C. Benzene hexachloride D. Alkyl benzene sulphonate (ABS)...

Foaming and priming in boiler operation can be reduced by reduction in ______________ in feed water?

A. Turbidity B. Color (Hazen) C. Total solids D. All A., B. & C....

Aerobic biological oxidation ponds used for the purification of polluted water__________________?

A. Destroys/removes pathogen from the sewage B. Is not very effective for non-biodegradable substances (e.g. ABS) containing effluents C. Destroys/removes pathogen much more effectively if the sewage is chlorinated D. All A., B. & C....