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_________________?

Related Mcqs:

Global warming may result in __________________?

A. Flood B. Cyclone C. Decrease in food productivity D. All A., B. and C....

Particles having diameter greater than 75 μm (micrometer = 10-6 mm) are called__________________?

A. Grit B. Dust C. Powder D. Smoke...

Noise level inside a jet airliner in normal flight is about ______________ decibels?

A. 80 B. 100 C. 125 D. 150...

Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of _____________ present in it?

A. Coal ash B. Potassium cyanide C. Ortho-xylene D. None of these...

Exposure to small amount of ______________ results in high blood pressure & heart disease in human beings?

A. Hydrogen sulphide B. Mercury C. Cadmium D. Asbestos...