Carbonaceous particles having size less than 1 μm are called (A) Grit (B) Aggregates (C) Aerosols (D) Smoke

Carbonaceous particles having size less than 1 μm are called
(A) Grit
(B) Aggregates
(C) Aerosols
(D) Smoke
by

1 Answer

Answer :

(D) Smoke
by

Related questions

Particles having diameter greater than 75 μm (micrometer = 10 -6 mm) are called (A) Grit (B) Dust (C) Powder (D) Smoke

Description : Particles having diameter greater than 75 μm (micrometer = 10 -6 mm) are called (A) Grit (B) Dust (C) Powder (D) Smoke

Last Answer : (A) Grit

5-200 μm size particles are called (A) Colloids or aerosols (B) Powder (C) Dust (D) Smoke

Description : 5-200 μm size particles are called (A) Colloids or aerosols (B) Powder (C) Dust (D) Smoke

Last Answer : (A) Colloids or aerosols

80% less than 200 mesh size particles are called (A) Smoke (B) Powder (C) Grit (D) Aggregates

Description : 80% less than 200 mesh size particles are called (A) Smoke (B) Powder (C) Grit (D) Aggregates

Last Answer : (B) Powder

Assertion (A) : Some carbonaceous aerosols may be carcinogenic. Reason (R) : They may contain polycyclic aromatic hydrocarbons (PAHs). (A) Both (A) and (R) are correct and (R) is the correct explanation of (A). (B) Both (A) and (R) are correct but (R) is not the correct explanation of (A). (C) (A) is correct, but (R) is false. (D) (A) is false, but (R) is correct.

Description : Assertion (A) : Some carbonaceous aerosols may be carcinogenic. Reason (R) : They may contain polycyclic aromatic hydrocarbons (PAHs). (A) Both (A) and (R) are correct and (R) is the correct explanation of (A). (B) Both ... (C) (A) is correct, but (R) is false. (D) (A) is false, but (R) is correct.

Last Answer : Answer: A

The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μm is (A) 6.35 kWh/ton (B) 9.0 kWh/ton (C) 18 kWh/ton (D) 25.4 kWh/ton

Description : The energy required per unit mass to grind limestone particles of very large size to 100 μm is 12.7 kWh/ton. An estimate (using Bond's law) of the energy to grind the particles from a very large size to 50 μm is (A) 6.35 kWh/ton (B) 9.0 kWh/ton (C) 18 kWh/ton (D) 25.4 kWh/ton

Last Answer : (C) 18 kWh/ton

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below : Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, the minimum fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle ... fluidisation velocity, VOM is (A) 12 mm/s (B) 16 mm/s (C) 24 mm/s (D) 28 mm/s

Last Answer : (B) 16 mm/s

A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system (in SI units) is given below: Δ P/L = 375 × 10 3 VOM + 10.94 × 10 6 V2 OM (SI units) If water is to be used as the fluidising medium, in actual operation, the above bed has a height = 1 m. What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Description : A bed of spherical particles (specific gravity 2.5) of uniform size 1500 μm is 0.5 m in diameter and 0.5 m high. In packed bed state, the porosity may be taken as 0.4. Ergun's equation for the above fluid-particle system ... What is the porosity of the fluidised bed? (A) 0.2 (B) 0.5 (C) 0.7 (D) 0.8

Last Answer : (C) 0.7

Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called (A) Fumes (B) Mists (C) Smoke (D) Aerosols

Description : Particulates (< 1μm size) remaining suspended in air indefinitely and transported by wind currents are called (A) Fumes (B) Mists (C) Smoke (D) Aerosols

Last Answer : (D) Aerosols

Particulates (< 1 µm size) remaining suspended in air indefinitely and transported by wind currents are called (1) Mists (2) Fumes (3) Aerosols (4) Smoke

Description : Particulates (< 1 µm size) remaining suspended in air indefinitely and transported by wind currents are called (1) Mists (2) Fumes (3) Aerosols (4) Smoke

Last Answer : Aerosols

A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is (A) 0.90 μm/s (B) 1 μm/s (C) 22.1 μm/s (D) 0.02 μm/s

Description : A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is (A) 0.90 μm/s (B) 1 μm/s (C) 22.1 μm/s (D) 0.02 μm/s

Last Answer : (B) 1 μm/s

Surface preparation for Metallising the abrasives used for final cleaning is a) Chilled iron grit G.24, as defined in BS : 2451 b) Washed salt free angular silica sand of mesh size 12 to 30 with a minimum of 40% retained on a 20 mesh c) either (a) or (b) * d) d) neither (a) or (b)

Description : Surface preparation for Metallising the abrasives used for final cleaning is a) Chilled iron grit G.24, as defined in BS : 2451 b) Washed salt free angular silica sand of mesh size 12 to 30 with a minimum of 40% retained on a 20 mesh c) either (a) or (b) * d) d) neither (a) or (b)

Last Answer : c) either (a) or (b) *

Asphalts are(A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Description : Asphalts are (A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Last Answer : (C) Readily oxidisable and form carbonaceous sludge

The maximum percentage of CO2 in a flue gas (from a carbonaceous fuel) can be(A) 21(B) 77(C) 79(D) 29

Description : The maximum percentage of CO2 in a flue gas (from a carbonaceous fuel) can be (A) 21 (B) 77 (C) 79 (D) 29

Last Answer : (A) 21

A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2 . It means that (A) 21% excess air has been used for combustion (B) 21% excess oxygen has been used for combustion (C) Complete combustion of fuel has taken place (D) No excess air has been used for combustion

Description : A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2 . It means that (A) 21% excess air has been used for combustion (B) 21% excess oxygen has ... (C) Complete combustion of fuel has taken place (D) No excess air has been used for combustion

Last Answer : (C) Complete combustion of fuel has taken place

Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in (A) Coagulation and flocculation of colloids (B) Oxidation of carbonaceous matter to CO2 (C) Nitrification or oxidation of ammonia derived from breakdown of nitrogenous organic matter to the nitrite and eventually to the nitrate (D) All (A), (B) and (C)

Description : Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in (A) Coagulation and flocculation of colloids (B) Oxidation of carbonaceous matter to CO2 (C) ... to the nitrite and eventually to the nitrate (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Presence of carbonaceous matter in the sewage (A) Causes reduction in its dissolved oxygen content thereby endangering the life of aquatic creatures (B) Reduces sulphate ions to sulphides causing obnoxious smell (C) Increases the quantity of chlorine used for its purification (D) All (A), (B) and (C)

Description : Presence of carbonaceous matter in the sewage (A) Causes reduction in its dissolved oxygen content thereby endangering the life of aquatic creatures (B) Reduces sulphate ions to sulphides causing obnoxious ... quantity of chlorine used for its purification (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

An excess of flaky particles in concrete aggregates (A) Decreases the workability (B) Increases the quantity of water and sand (C) More than 15% are not desirable (D) All the above

Description : An excess of flaky particles in concrete aggregates (A) Decreases the workability (B) Increases the quantity of water and sand (C) More than 15% are not desirable (D) All the above

Last Answer : Answer: Option D

Sulfuric acid aerosols from the eruption of Mt. Pinatubo reduced the rate of global warming last year. They also contributed to the record size of: w) acid rainfalls in Europe x) the anchovy catch off Peru y) the ozone hole over Antarctica z) fish kills in the Amazon River

Description : Sulfuric acid aerosols from the eruption of Mt. Pinatubo reduced the rate of global warming last year. They also contributed to the record size of: w) acid rainfalls in Europe x) the anchovy catch off Peru y) the ozone hole over Antarctica z) fish kills in the Amazon River

Last Answer : ANSWER: Y -- THE OZONE HOLE OVER ANTARCTICA

If aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60 mm, the particular aggregate will be flaky if its minimum dimension is less than (A) 20.5 mm (B) 30.5 mm (C) 40.5 mm (D) 50.5 mm

Description : If aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60 mm, the particular aggregate will be flaky if its minimum dimension is less than (A) 20.5 mm (B) 30.5 mm (C) 40.5 mm (D) 50.5 mm

Last Answer : Answer: Option C

Aerosols having carbon and fluorine compounds are chiefly released by

Description : Aerosols having carbon and fluorine compounds are chiefly released by

Last Answer : Aerosols having carbon and fluorine compounds are chiefly released by A. Refineries B. Automobiles C. Industries D. Jets.

Aerosols having carbon and fluorine compounds are chiefly released by: (a) Refineries (b) Automobiles (c) Industries (d) Jets 3. Coir of commerce is obtained from: (a) Endocarp of coconut (b) Mesocarp of coconut (c) Stem of jute (d) Leaves of coconut

Description : Aerosols having carbon and fluorine compounds are chiefly released by: (a) Refineries (b) Automobiles (c) Industries (d) Jets 3. Coir of commerce is obtained from: (a) Endocarp of coconut (b) Mesocarp of coconut (c) Stem of jute (d) Leaves of coconut

Last Answer : Ans. ((d))

In what sizes of particles the aggregates are deficient or Oversupplied How Might this be Remedied in a practical way?

Description : In what sizes of particles the aggregates are deficient or Oversupplied How Might this be Remedied in a practical way?

Last Answer : If you sell the wrong sizes the customers will return theproducts and want their money back. This will remedy the problem asyou will go out of business.

For given water content, workability decreases if the concrete aggregates contain an excess of (A) Thin particles (B) Flat particles (C) Elongated particles (D) All the above

Description : For given water content, workability decreases if the concrete aggregates contain an excess of (A) Thin particles (B) Flat particles (C) Elongated particles (D) All the above

Last Answer : (D) All the above

Pick up the correct statement from the following: (A) According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight (B) According to the shape of the particles, concrete aggregates are classified as rounded irregular, angular and flaky (C) According to the surface texture of the particles, the concrete aggregates are classified as glassy, smooth, granular, rough, crystalline, honey combed and porous (D) All the above

Description : Pick up the correct statement from the following: (A) According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight (B) According to ... glassy, smooth, granular, rough, crystalline, honey combed and porous (D) All the above

Last Answer : Answer: Option D

If a grading curve is horizontal between the portions of 20 mm I.S. Sieve and 4.75 mm I.S. Sieve, the graded aggregates do not contain (A) 20 mm particles (B) 10 mm particles (C) 4.75 mm particles (D) All the above

Description : If a grading curve is horizontal between the portions of 20 mm I.S. Sieve and 4.75 mm I.S. Sieve, the graded aggregates do not contain (A) 20 mm particles (B) 10 mm particles (C) 4.75 mm particles (D) All the above

Last Answer : Answer: Option D

For reinforced concrete work, aggregates having a nominal size of -------- are generally used [ A ] 20 mm [ B ] 40 mm [ C ] 50 mm [ D ] 60 mm

Description : For reinforced concrete work, aggregates having a nominal size of -------- are generally used [ A ] 20 mm [ B ] 40 mm [ C ] 50 mm [ D ] 60 mm

Last Answer : [ A ] 20 mm

The type of aggregates of same nominal size, which contain less voids when compacted, are (A) Rounded spherical (B) Irregular (C) Flaky (D) None of these

Description : The type of aggregates of same nominal size, which contain less voids when compacted, are (A) Rounded spherical (B) Irregular (C) Flaky (D) None of these

Last Answer : Answer: Option A

Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to A. Initial demand B. First stage demand C. Carbonaceous demand D. All of these

Description : Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to A. Initial demand B. First stage demand C. Carbonaceous demand D. All of these

Last Answer : ANS: D

Combustion of pulverised fuel (A) Requires larger combustion chamber than rich gaseous fuel (B) In a metallurgical furnace does not contaminate the product in the furnace by ash from fuel (C) Suppresses the discharge of fine dust and grit into atmosphere (D) All (A), (B) and (C)

Description : Combustion of pulverised fuel (A) Requires larger combustion chamber than rich gaseous fuel (B) In a metallurgical furnace does not contaminate the product in the furnace by ash from fuel (C) Suppresses the discharge of fine dust and grit into atmosphere (D) All (A), (B) and (C)

Last Answer : (A) Requires larger combustion chamber than rich gaseous fuel

__________ substances present in sewage are removed in grit chamber during sewage treatment. (A) Organic (B) Fatty(C) Inorganic(D) Dissolved

Description : __________ substances present in sewage are removed in grit chamber during sewage treatment. (A) Organic (B) Fatty (C) Inorganic (D) Dissolved

Last Answer : (C) Inorganic

Fine grit present in sewage is removed in the __________ during sewage treatment. (A) Grit chamber (B) Detritus tank (C) Trickling filter (D) Skimming tank

Description : Fine grit present in sewage is removed in the __________ during sewage treatment. (A) Grit chamber (B) Detritus tank (C) Trickling filter (D) Skimming tank

Last Answer : (B) Detritus tank

Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 cm and 1.7 mm B. 5 mm and 2.5 mm C. 5 cm and 2.5 cm D. 1.35 mm and 1.7 μm

Description : Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 cm and 1.7 mm B. 5 mm and 2.5 mm C. 5 cm and 2.5 cm D. 1.35 mm and 1.7 μm

Last Answer : B. 5 mm and 2.5 mm

Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 mm and 1.7 μm B. 1.35 cm and 1.7 mm C. 5 cm and 2.5 cm D. 5 mm and 2.5 mm

Description : Oxygen molecule absorption peaks to electromagnetic wave are at what wavelengths? A. 1.35 mm and 1.7 μm B. 1.35 cm and 1.7 mm C. 5 cm and 2.5 cm D. 5 mm and 2.5 mm

Last Answer : D. 5 mm and 2.5 mm

Calculate the static deflection in μm of transverse vibrations if the frequency is 200Hz. A. 6.21 B. 0.621 C. 62.1 D. 0.006

Description : Calculate the static deflection in μm of transverse vibrations if the frequency is 200Hz. A. 6.21 B. 0.621 C. 62.1 D. 0.006

Last Answer : A. 6.21

Calculate the static deflection in μm of transverse vibrations if the frequency is 200Hz. a) 6 b) 0.6 c) 60 d) 0.006

Description : Calculate the static deflection in μm of transverse vibrations if the frequency is 200Hz. a) 6 b) 0.6 c) 60 d) 0.006

Last Answer : a) 6

The length of each mitochondrion is about (A) 1.0 μm (B) 0.2 μm (C) 10 μm (D) 2.0 μm

Description : The length of each mitochondrion is about (A) 1.0 μm (B) 0.2 μm (C) 10 μm (D) 2.0 μm

Last Answer : (C) 10 μm

Aerosols present in atmospheric air may be (A) Positively charged (B) Negatively charged (C) Neutral (D) Combination of all (A), (B) & (C)

Description : Aerosols present in atmospheric air may be (A) Positively charged (B) Negatively charged (C) Neutral (D) Combination of all (A), (B) & (C)

Last Answer : (D) Combination of all (A), (B) & (C)

Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air's water vapor condenses on the solid particles of smoke thereby forming smog (smoke + fog), it causes (A) Poor visibility due to sky darkening (B) Irritation in eyes (C) Respiratory trouble (D) All (A), (B) and (C)

Description : Sooty and sulphurous smog formed due to combustion of fossil fuels particularly in winter, continues throughout the day and night. When the moist atmospheric air's water vapor condenses on the solid particles of smoke thereby ... B) Irritation in eyes (C) Respiratory trouble (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Is grit igneous sedimentary or metamorphic?

Description : Is grit igneous sedimentary or metamorphic?

Last Answer : idk maybe sedimantary?????

Is grit igneous sedimentary or metamorphic?

Description : Is grit igneous sedimentary or metamorphic?

Last Answer : idk maybe sedimantary?????

Hello, I found your company on the internet. Apparently you do chrome plating Could you give me a quote to chrome plate the headlight ears (2) on my vintage BSA motorcycle I have removed all paint and sanded them with 220 grit. Kenny (in the Black Hills?

Description : Hello, I found your company on the internet. Apparently you do chrome plating Could you give me a quote to chrome plate the headlight ears (2) on my vintage BSA motorcycle I have removed all paint and sanded them with 220 grit. Kenny (in the Black Hills?

Last Answer : I found one shop in your area that might: Pierre's Body Shop located at 1304 S Cliff Ave in Sioux Falls.

If the grit in grit chambers is 4.5 million litres per day, its cleaning is done A. Manually B. Mechanically C. Hydraulically D. Electrically

Description : If the grit in grit chambers is 4.5 million litres per day, its cleaning is done A. Manually B. Mechanically C. Hydraulically D. Electrically

Last Answer : ANS: A

The recommended detention period for grit chambers is A. 1 minute B. 2 minutes C. 3 minutes D. 5 minutes

Description : The recommended detention period for grit chambers is A. 1 minute B. 2 minutes C. 3 minutes D. 5 minutes

Last Answer : ANS: A

In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above

Description : In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above

Last Answer : ANS: D

The grit chambers of sewage treatment plants, are generally cleaned after A. 2 days B. 7 days C. 12 days D. 14 days

Description : The grit chambers of sewage treatment plants, are generally cleaned after A. 2 days B. 7 days C. 12 days D. 14 days

Last Answer : ANS: D

Skimming tanks are A. Used to remove the grease and oil B. Those from which sludge is skimmed out C. Tanks provided with self- cleansing screens D. Improved version of grit chambers

Description : Skimming tanks are A. Used to remove the grease and oil B. Those from which sludge is skimmed out C. Tanks provided with self- cleansing screens D. Improved version of grit chambers

Last Answer : ANS: A

The grit and silt of the grit chambers, may not be used for A. Raising low lying areas by dumping B. Concreting C. Both A. and B. D. Neither A. nor B.

Description : The grit and silt of the grit chambers, may not be used for A. Raising low lying areas by dumping B. Concreting C. Both A. and B. D. Neither A. nor B.

Last Answer : ANS: B

For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is A. 16 m B. 20 m C. 24 m D. 30 m

Description : For a grit chamber, if the recommended velocity of flow is 0.2 m/sec and detention period is 2 minutes, the length of the tank, is A. 16 m B. 20 m C. 24 m D. 30 m

Last Answer : ANS: C

Indicate which of the statement is incorrect (a) The detritus tank is type of a grit chamber (b) In detritus tank, velocity of flow is further reduced (c) Grit chambers are provided in the sewage treatment process to remove the heavier inorganic matter as grit, sand etc. from the sewage (d) None of them*

Description : Indicate which of the statement is incorrect (a) The detritus tank is type of a grit chamber (b) In detritus tank, velocity of flow is further reduced (c) Grit chambers are provided in the sewage ... to remove the heavier inorganic matter as grit, sand etc. from the sewage (d) None of them*

Last Answer : (d) None of them*

Bond crushing law (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law (B) Is less realistic in estimating the power requirements of commercial crushers (C) States that the work required to form particle of any size from very large feed is proportional to the square root of the volume to surface ratio of the product (D) States that the work required for the crushing is proportional to the new surface created

Description : Bond crushing law (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law (B) Is less realistic in estimating the power requirements of commercial crushers ( ... (D) States that the work required for the crushing is proportional to the new surface created

Last Answer : (A) Calls for relatively less energy for the smaller product particles, than does the Rittinger law