Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about ____________ decibels?

Related Mcqs:

1. The major reason of hydrodynamic noise (i.e., noise resulting from liquid flow) is_________________?

   A. Pipe vibrations
   B. Cavitation
   C. Boundary layer separation
   D. Fluctuation in liquid flow

2. Aerodynamic noise resulting from turbulent gas flow is the most prevalent source of valve noise in fluid flow control. It is caused due to_________________?

   A. Reynold stresses
   B. Shear forces
   C. Both A. & B.
   D. Neither A. nor B.

3. A man exposed to excessive noise level in the working environment may suffer from____________________?

   A. Hearing loss
   B. Rupture of ear drum
   C. Nervousness & fatigue
   D. All A., B. & C.

4. The maximum permissible noise level to which a man working in a chemical plant can be exposed for eight hours per day is about ____________ decibels?

   A. 60
   B. 90
   C. 105
   D. 120

5. A perfectly insulated container of volume V is divided into two equal halves by a partition. One side is under vacuum, while the other side has one mole of an ideal gas (with constant heat capacity) at 298 K. If the partition is broken, the final temperature of the gas in the container___________________?

   A. Will be greater than 298 K
   B. Will be 298 K
   C. Will be less than 298 K
   D. Cannot be determined

6. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is____________________?

   A. 100,000 kW
   B. 160,000 kW
   C. 200,000 kW
   D. 320,000 kW

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

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

8. Noise level during normal conversation among men is about ______________ decibels?

   A. 10
   B. 45
   C. 90
   D. 115

9. 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.

10. Noise pollution level in a chemical plant is expressed in __________________?

    A. Roentgen
    B. Decibel
    C. Hertz
    D. None of these