Gaseous diffusivity at atmospheric pressure is of the order of __________ cm2 /second. (A) 1 (B) 1 to 5 (C) 5 to 10 (D) > 10

Gaseous diffusivity at atmospheric pressure is of the order of
__________ cm2
/second.
(A) 1
(B) 1 to 5
(C) 5 to 10
(D) > 10
by

1 Answer

Answer :

(A) 1
by

Related questions

Liquid diffusivity is of the order of __________ cm2 /second. (A) 0.01 (B) 0.1 (C) 10 -5 to 10 -6 (D) > 1

Description : Liquid diffusivity is of the order of __________ cm2 /second. (A) 0.01 (B) 0.1 (C) 10 -5 to 10 -6 (D) > 1

Last Answer : (C) 10 -5 to 10

The binary diffusivity in gases at atmospheric conditions is about (A) 10 -9 cm/sec (B) 10 -1 cm2 /sec (C) 10 -3 sec/cm (D) 10 -4 cm2 /sec

Description : The binary diffusivity in gases at atmospheric conditions is about (A) 10 -9 cm/sec (B) 10 -1 cm2 /sec (C) 10 -3 sec/cm (D) 10 -4 cm2 /sec

Last Answer : (B) 10 -1 cm2 /sec

Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids (C) Particles movement from higher concentration to lower concentration takes place in diffusion process (D) According to Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary

Description : Pick out the wrong statement. (A) The binary diffusivity in liquids is of the order of 10 -5 cm2 /sec (B) Molecular diffusion in solid is much faster than that in liquids ( ... Poiseuille's law, the permeability decreases with increase in temperature for flow of a gas through a given capillary

Last Answer : (B) Molecular diffusion in solid is much faster than that in liquids

The gaseous form of chlorine gets converted into liquid form when subjected to a pressure of (A) 5 kg/cm2 (B) 6 kg/cm2 (C) 7 kg/cm2 (D) 10 kg/cm

Description : The gaseous form of chlorine gets converted into liquid form when subjected to a pressure of  (A) 5 kg/cm2 (B) 6 kg/cm2 (C) 7 kg/cm2 (D) 10 kg/cm

Last Answer : (C) 7 kg/cm

The unit of volumetric diffusivity is (A) cm2 /sec (B) cm/sec (C) cm3 /sec (D) cm2 /sec

Description : The unit of volumetric diffusivity is (A) cm2 /sec (B) cm/sec (C) cm3 /sec (D) cm2 /sec

Last Answer : (A) cm2 /sec

Primary purpose of a __________ nuclear reactor is to supply a high neutron flux of the order of 10 13 to 10 14neutrons/cm2 second. (A) Research (B) Power (C) Breeder (D) Homogeneous

Description : Primary purpose of a __________ nuclear reactor is to supply a high neutron flux of the order of 10 13 to 10 14neutrons/cm2 second. (A) Research (B) Power (C) Breeder (D) Homogeneous

Last Answer : (A) Research

Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at 35°C (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C (C) Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C (D) A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C

One barometric pressure or 1 atmospheric pressure is equal to  (a) 1 kgf/cnr2  (b) 1.033 kgf/cm2  (c) 0 kgf/cm2  (d) 1.0197 kgf/cm2  (e) 100 kgf/cm2.

Description : One barometric pressure or 1 atmospheric pressure is equal to  (a) 1 kgf/cnr2  (b) 1.033 kgf/cm2  (c) 0 kgf/cm2  (d) 1.0197 kgf/cm2  (e) 100 kgf/cm2.

Last Answer : Answer : b

n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In each batch about 120 kgs of material is dried. a. The quantity of moisture removed per batch. b. What is the total quantity ( sensible & latent) of heat required to evaporate the moisture, if the latent heat of water is 540 kcal/kg at atmospheric conditions, Ignore heat absorbed by the solids c. Find the quantity of steam required for the drying process (per batch), if steam at 4 kg/cm2 is used for generating hot air in the dryer and the dryer efficiency is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.

Description : n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture  is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In  each batch about 120 ... dryer and the dryer efficiency  is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.

Last Answer : Given that   Qty of material dried per batch - 120 Kgs  Moisture at inlet - 60% a. The quantity of moisture removed per batch.  Water quantity in a wet batch - 120 x 0.6 = 72 Kgs.  Quantity of bone dry ... - 48/0.95 = 50.5 Kgs.  Equivalent water in a dry batch - 50.5 - 48 = 2.5 Kgs.

The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________ (A) 1 (B) 0.5 (C) 10 (D) 0

Description : The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are same for, NPr = NSc = __________ (A) 1 (B) 0.5 (C) 10 (D) 0

Last Answer : (A) 1

The effectiveness factor for large value of Thiele modulus [L√(K/D1 )] of a solid catalysed first order reaction is equal to (where, L = length of the reactor, cm, D1 = diffusion co-efficient, cm2 /second). (A) L √(K/D1 ) (B) 1/[L√(K/D1 )] (C) 1 (D) ∞

Description : The effectiveness factor for large value of Thiele modulus [L√(K/D1 )] of a solid catalysed first order reaction is equal to (where, L = length of the reactor, cm, D1 = diffusion co-efficient, cm2 /second). (A) L √(K/D1 ) (B) 1/[L√(K/D1 )] (C) 1 (D) ∞

Last Answer : (B) 1/[L√(K/D1 )]

The conversion in a mixed reactor/accomplishing a reaction A → 3R is 50% when gaseous reactant 'A' is introduced at the rate of 1 litre/second and the leaving flow rate is 2 litres/second. The holding time for this operation is __________ second. (A) 0.5 (B) 1 (C) 2(D) 3

Description : The conversion in a mixed reactor/accomplishing a reaction A → 3R is 50% when gaseous reactant 'A' is introduced at the rate of 1 litre/second and the leaving flow rate is 2 litres/second. The holding time for this operation is __________ second. (A) 0.5 (B) 1 (C) 2 (D) 3

Last Answer : (A) 0.5

high pressure boiler generates steam at a pressure greater than __________ kg/cm2. (A) 10 (B) 30 (C) 50 (D) 80

Description : high pressure boiler generates steam at a pressure greater than __________ kg/cm2. (A) 10 (B) 30 (C) 50 (D) 80

Last Answer : Option D

A gaseous reactant is introduced in a mixed reactor of 3 litres volume at the rate of 1 litre/second. The space time is __________ seconds. (A) 1 (B) 3 (C) 1/3 (D) 32

Description : A gaseous reactant is introduced in a mixed reactor of 3 litres volume at the rate of 1 litre/second. The space time is __________ seconds. (A) 1 (B) 3 (C) 1/3 (D) 32

Last Answer : (B) 3

Pressure maintained in the high pressure primary tower of a three stage crude oil distillation system is about __________ kg/cm2 . (A) 1.5 (B) 3 (C) 6 (D) 12

Description : Pressure maintained in the high pressure primary tower of a three stage crude oil distillation system is about __________ kg/cm2 . (A) 1.5 (B) 3 (C) 6 (D) 12

Last Answer : (B) 3

For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the (A) Catalyst size is reduced or the catalyst diffusivity is reduced (B) Catalyst size is reduced or the catalyst diffusivity is increased (C) Catalyst size is increased or the catalyst diffusivity is reduced(D) Catalyst size is increased or the catalyst diffusivity is increased

Description : For a first order isothermal chemical reaction in a porous catalyst, the effectiveness factor is 0.3. The effectiveness factor will increase if the (A) Catalyst size is reduced or the ... the catalyst diffusivity is reduced (D) Catalyst size is increased or the catalyst diffusivity is increased

Last Answer : (B) Catalyst size is reduced or the catalyst diffusivity is increased

In a mixer, the quantity, (v. L/D) is termed as __________ number (where, v = longitudinal velocity of material, L = length of the mixer, D = diffusivity in axial mixing). (A) Weber (B) Peclet (C) Brinkman (D) Schmidt

Description : In a mixer, the quantity, (v. L/D) is termed as __________ number (where, v = longitudinal velocity of material, L = length of the mixer, D = diffusivity in axial mixing). (A) Weber (B) Peclet (C) Brinkman (D) Schmidt

Last Answer : (B) Peclet

Laboratory determination of the diffusivity of vapor is done by __________ method. (A) Wetted wall column (B) Gilliland's (C) Winkelmann's (D) Wike's

Description : Laboratory determination of the diffusivity of vapor is done by __________ method. (A) Wetted wall column (B) Gilliland's (C) Winkelmann's (D) Wike's

Last Answer : (C) Winkelmann's

The ratio of momentum diffusivity to thermal diffusivity is the __________ number. (A) Prandtl (B) Nusselt (C) Stanton (D) Grashoff

Description : The ratio of momentum diffusivity to thermal diffusivity is the __________ number. (A) Prandtl (B) Nusselt (C) Stanton (D) Grashoff

Last Answer : (A) Prandtl

The ratio of kinematic viscosity to thermal diffusivity is called the __________ number. (A) Peclet (B) Prandtl (C) Stanton (D) Nusselt

Description : The ratio of kinematic viscosity to thermal diffusivity is called the __________ number. (A) Peclet (B) Prandtl (C) Stanton (D) Nusselt

Last Answer : (B) Prandtl

1. __________ of air does not increase with increase in temperature. (A) Density (B) Thermal diffusivity (C) Viscosity (D) Thermal conductivi

Description : 1. __________ of air does not increase with increase in temperature. (A) Density (B) Thermal diffusivity (C) Viscosity (D) Thermal conductivi

Last Answer : Option A

Pressure of CO2 gas (which is a coolant) in the Calder-Hall nuclear reactor is __________ kgf/cm2 . (A) 0.2 (B) 7 (C) 35 (D) 50

Description : Pressure of CO2 gas (which is a coolant) in the Calder-Hall nuclear reactor is __________ kgf/cm2 . (A) 0.2 (B) 7 (C) 35 (D) 50

Last Answer : (B) 7

The maximum delivery pressure of a reciprocating compressor may be about __________ kg/cm2 . (A) 1000 (B) 2000 (C) 3000 (D) 4000

Description : The maximum delivery pressure of a reciprocating compressor may be about __________ kg/cm2 . (A) 1000 (B) 2000 (C) 3000 (D) 4000

Last Answer : (D) 4000

__________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm2 . (A) Centrifugal (B) Piston (C) Plunger (D) Vane

Description : __________ pump is the most suitable device for discharging a liquid against a pressure of ≥ 1500 kgf/cm2 . (A) Centrifugal (B) Piston (C) Plunger (D) Vane

Last Answer : (C) Plunger

The critical pressure at which the latent heat of vaporisation of steam becomes zero is __________ Kg/cm2. (A) 273.15 (B) 225.65 (C) 100.03 (D) 373.15

Description : The critical pressure at which the latent heat of vaporisation of steam becomes zero is __________ Kg/cm2. (A) 273.15 (B) 225.65 (C) 100.03 (D) 373.15

Last Answer : (B) 225.65

A fire tube boiler is limited to a maximum steam pressure of about __________ kg/cm2. (A) 6 (B) 18 (C) 38 (D) 52

Description : A fire tube boiler is limited to a maximum steam pressure of about __________ kg/cm2. (A) 6 (B) 18 (C) 38 (D) 52

Last Answer : (B) 18

With an increase in pressure in gaseous phase chemical reactions, the fractional conversion __________ when the number of moles decreases. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Description : With an increase in pressure in gaseous phase chemical reactions, the fractional conversion __________ when the number of moles decreases. (A) Increases (B) Decreases (C) Remain unaffected (D) Unpredictable from the data

Last Answer : (A) Increases

The binary diffusivity in gases does not depend upon the (A) Pressure (B) Temperature (C) Nature of the components (D) None of these

Description : The binary diffusivity in gases does not depend upon the (A) Pressure (B) Temperature (C) Nature of the components (D) None of these

Last Answer : (D) None of these

In case of liquid-liquid binary diffusion, diffusivity of one constituent into another is not dependent on the (A) Temperature and pressure (B) Concentration (C) Nature of the constituents (D) None of these

Description : In case of liquid-liquid binary diffusion, diffusivity of one constituent into another is not dependent on the (A) Temperature and pressure (B) Concentration (C) Nature of the constituents (D) None of these

Last Answer : (D) None of these

In case of gases, the binary diffusivity is proportional to (where, P = pressure). (A) P (B) 1/P (C) 1/√P (D) √P

Description : In case of gases, the binary diffusivity is proportional to (where, P = pressure). (A) P (B) 1/P (C) 1/√P (D) √P

Last Answer : (B) 1/P

Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the (A) Mass transfer co-efficient (B) Thermal diffusivity (C) Kinematic viscosity (D) Volumetric diffusivity

Description : Diffusion co-efficient generally depends upon the temperature, pressure & the nature of the components of the system. Its dimension is not the same as that of the (A) Mass transfer co-efficient (B) Thermal diffusivity (C) Kinematic viscosity (D) Volumetric diffusivity

Last Answer : (A) Mass transfer co-efficient

In case of non-ideal gases and liquids, the molal diffusivity (A) Varies inversely as the pressure (B) Varies directly as the pressure (C) Is independent of pressure (D) Is equal to the volumetric diffusivity

Description : In case of non-ideal gases and liquids, the molal diffusivity (A) Varies inversely as the pressure (B) Varies directly as the pressure (C) Is independent of pressure (D) Is equal to the volumetric diffusivity

Last Answer : (C) Is independent of pressure

Dimension of mass diffusivity is the same as that of (A) Kinematic viscosity (B) Dynamic viscosity (C) Surface tension (D) Pressure

Description : Dimension of mass diffusivity is the same as that of (A) Kinematic viscosity (B) Dynamic viscosity (C) Surface tension (D) Pressure

Last Answer : (A) Kinematic viscosity

If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : If the catalyst pore size is small in comparison with the mean free path, collisions with the pore wall controls the process'. The diffusivity under this condition is called 'Knudsen diffusivity', which is affected by the (A) Pressure (B) Temperature (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (B) Temperature

Approximate value of the modulus of elasticity for steel is about __________ × 10 6kg/cm2 . (A) 0.5 (B) 2 (C) 40 (D) 75

Description : Approximate value of the modulus of elasticity for steel is about __________ × 10 6kg/cm2 . (A) 0.5 (B) 2 (C) 40 (D) 75

Last Answer : (B) 2

Current employed in resistance welding ranges from __________ kVA/cm2. (A) 1.2 to 2.5 (B) 4.5 to 6.2 (C) 7.5 to 8.5 (D) 10.5 to 15.5

Description : Current employed in resistance welding ranges from __________ kVA/cm2. (A) 1.2 to 2.5 (B) 4.5 to 6.2 (C) 7.5 to 8.5 (D) 10.5 to 15.5

Last Answer : Option B

Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about __________ percent. (A) < 2 (B) < 5 (C) < 8 (D) < 10

Description : Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about __________ percent. (A) < 2 (B) < 5 (C) < 8 (D) < 10

Last Answer : (A) < 2

Crude topping column operates at __________ pressure. (A) Atmospheric (B) 10 atm

Description : Crude topping column operates at __________ pressure. (A) Atmospheric (B) 10 atm

Last Answer : (A) Atmospheric

Operating temperature and pressure in catalytic reforming is about (A) 1-5 Kgf/cm2 & 200°C (B) 15-45 Kgf/cm2 & 450-550°C (C) 50 - 75 kgf/cm2 & 600 - 800°C (D) 5-10 kgf/cm2 & 150 - 250°C

Description : Operating temperature and pressure in catalytic reforming is about (A) 1-5 Kgf/cm2 & 200°C (B) 15-45 Kgf/cm2 & 450-550°C (C) 50 - 75 kgf/cm2 & 600 - 800°C (D) 5-10 kgf/cm2 & 150 - 250°C

Last Answer : (B) 15-45 Kgf/cm2 & 450-550°C

Temperature and gage pressure maintained during the manufacture of hot SBR (styrene butadiene rubber) are (A) 50°C and 3 - 4 kg/cm2 (B) 50°C and 1 kgf/cm2 (C) 250°C and 10 kgf/cm2 (D) 250°C and 1 kgf/cm

Description : Temperature and gage pressure maintained during the manufacture of hot SBR (styrene butadiene rubber) are (A) 50°C and 3 - 4 kg/cm2 (B) 50°C and 1 kgf/cm2 (C) 250°C and 10 kgf/cm2 (D) 250°C and 1 kgf/cm

Last Answer : (A) 50°C and 3 - 4 kg/cm

The pressure (kg/cm2 ) and temperature (°C) maintained in electrical desalters for crude oil are respectively (A) 10 and 120 (B) 1 and 200 (C) 50 and 250 (D) 10 and 300

Description : The pressure (kg/cm2 ) and temperature (°C) maintained in electrical desalters for crude oil are respectively (A) 10 and 120 (B) 1 and 200 (C) 50 and 250 (D) 10 and 300

Last Answer : (B) 1 and 200

Though increased pressure has a retarding effect on cracking reaction, yet in actual process, a positive pressure of 10-15 kgf/cm2 is maintained during cracking mainly to (A) Increase the yield of light distillates (B) Suppress coke formation (C) Enhance the octane number of gasoline (D) Reduce gum content in gasoline

Description : Though increased pressure has a retarding effect on cracking reaction, yet in actual process, a positive pressure of 10-15 kgf/cm2 is maintained during cracking mainly to (A) Increase the yield of ... coke formation (C) Enhance the octane number of gasoline (D) Reduce gum content in gasoline

Last Answer : (B) Suppress coke formation

Vinyl chloride (CH2 = CH.Cl) is produced by the thermal pyrolysis of ethylene dichloride at a pressure & temperature of (A) 4 kgf/cm2 & 500°C (B) 10 kgf/cm2 & 1000°C (C) 40 kg/cm2 & 200°C (D) 100 kgf/cm2 & 500°C

Description : Vinyl chloride (CH2 = CH.Cl) is produced by the thermal pyrolysis of ethylene dichloride at a pressure & temperature of (A) 4 kgf/cm2 & 500°C (B) 10 kgf/cm2 & 1000°C (C) 40 kg/cm2 & 200°C (D) 100 kgf/cm2 & 500°C

Last Answer : (A) 4 kgf/cm2 & 500°C

. One stoke (unit of kinematic viscosity) is equivalent to (A) 1 cm2 /second (B) 1 m2 /second (C) 1 gm/cm. second (D) 1 kg. m/second

Description : . One stoke (unit of kinematic viscosity) is equivalent to (A) 1 cm2 /second (B) 1 m2 /second (C) 1 gm/cm. second (D) 1 kg. m/second

Last Answer : (A) 1 cm2 /second

The rough value of diffusion co-efficient of water vapor into air at 25°C may be about __________ cm2 /sec. (A) 0.25 (B) 2.5 (C) 1.25 (D) 0.0025

Description : The rough value of diffusion co-efficient of water vapor into air at 25°C may be about __________ cm2 /sec. (A) 0.25 (B) 2.5 (C) 1.25 (D) 0.0025

Last Answer : (A) 0.25

In the atmospheric pressure crude distillation, the content of __________ from lighter fraction to heavier ones. (A) Sulphur increases (B) Sulphur decreases (C) Nitrogen decreases (D) None of these

Description : In the atmospheric pressure crude distillation, the content of __________ from lighter fraction to heavier ones. (A) Sulphur increases (B) Sulphur decreases (C) Nitrogen decreases (D) None of these

Last Answer : (A) Sulphur increases

. Sodium melts (at atmospheric pressure) at a temperature of __________ °C. (A) 58 (B) 98 (C) 348 (D) 588

Description : . Sodium melts (at atmospheric pressure) at a temperature of __________ °C. (A) 58 (B) 98 (C) 348 (D) 588

Last Answer : (B) 98

Water-ethyl alcohol solution can be concentrated (in respect of alcohol concentration) by __________ distillation. (A) Atmospheric (B) Vacuum (C) High pressure (D) None of these

Description : Water-ethyl alcohol solution can be concentrated (in respect of alcohol concentration) by __________ distillation. (A) Atmospheric (B) Vacuum (C) High pressure (D) None of these

Last Answer : (B) Vacuum

Film boiling occurs at __________ pressure. (A) Atmospheric (B) Sub-atmospheric (C) Negative (D) Very high

Description : Film boiling occurs at __________ pressure. (A) Atmospheric (B) Sub-atmospheric (C) Negative (D) Very high

Last Answer : (D) Very high

Working principle of manometer comprises of balancing a coloumn of liquid against the pressure to be measured. Inclined tube manometer is especially used for the measurement of __________ pressure. (A) Small differential (B) Atmospheric (C) Absolute (D) Gage

Description : Working principle of manometer comprises of balancing a coloumn of liquid against the pressure to be measured. Inclined tube manometer is especially used for the measurement of __________ pressure. (A) Small differential (B) Atmospheric (C) Absolute (D) Gage

Last Answer : (A) Small differential