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31.

The collection efficiency of electrostatic precipitator

A.	increases with increase in the electrode area	B.	increases with increase in the particle drift velocity
C.	decreases with increase in the gas flow rate	D.	all of the above

32.

For most industrial electrostatic precipitator installations particledrift velocity which is used to calculate the precipitation efficiency varies from

A.	3 to 8 ft/s	B.	0.1 to 1 ft/s
C.	60 to 80 ft/s	D.	15 to 20 ft/s

33.

For heavy duty industrial type electrostatic precipitator

A.	from 30000 to 100000 volts dc is normally required	B.	from 240 to 440 volts dc is normally required
C.	from 13000 to 18000 volts dc is normally required	D.	from 1000 to 5000 volts dc is normally required

34.

For a fabric filter gas-to-fabric ratio is expressed as cubic feet per minute per square foot fabric surface area. As the gas-to-fabric ratio becomes larger

A.	the size and cost of a fabric filter is correspondingly increased	B.	the size and cost of a fabric fulter is correspondingly decreased
C.	the size and cost of a fabric filter remains unaffected

35.

Gas temperature is an important consideration in the design of fabric filter because it affects

A.	the gas viscosity	B.	the gas density
C.	the selection of fabric	D.	all of the above

36.

In a fabric filter the pressure drop

A.	increases directly as viscosity of the gas and inversely as density of the gas	B.	increases directly as density of the gas and inversely as viscosity of the gas
C.	increases directly as density of the gas and independent of the viscosity of the gas	D.	none of the above

37.

The resistance offered by filter used in a fabric filter

A.	varies inversely as the particle size and directly as the dust concentration	B.	varies inversely as the dust concentration and directly as the particle size
C.	varies directly as the particle size as well as the dust concentration	D.	varies inversely as the particle size as well as the dust concentration

38.

The operating pressure drops for a fabric filter are usually in the range of

A.	0.2 to 0.5 in. H2O g	B.	2 to 6 in. H2O g
C.	8 to 60 in. H2O g	D.	0.01 to 0.1 in. H2O g

39.

Depending on the size of the particles being collected the wet scrubbers operate in a pressure drop range from

A.	0.2 to 0.5 in. H2O g	B.	3 to 60 in. H2O g
C.	0.01 to 0.1 in. H2O g	D.	760 to 800 in. H2O g

40.

Which of the following devices of particulate collection is the least efficient?

A.	Cyclone separator	B.	Electrostatic precipitator
C.	Fabric filter	D.	Wet scrubber