A solid material shows case hardening properties while drying. Which of the following should be controlled to control the drying process? (A) Flow rate of inlet air (B) Relative humidity of outlet air (C) Humidity of inlet air (D) Temperature of the solid

A solid material shows case hardening properties while drying. Which
of the following should be controlled to control the drying process?
(A) Flow rate of inlet air
(B) Relative humidity of outlet air
(C) Humidity of inlet air
(D) Temperature of the solid
by

1 Answer

Answer :

(D) Temperature of the solid
by

Related questions

Occurrence of 'case hardening' during drying of a high moisture solid cake __________ the drying rate. (A) Increases (B) Decreases (C) Does not affect

Description : Occurrence of 'case hardening' during drying of a high moisture solid cake __________ the drying rate. (A) Increases (B) Decreases (C) Does not affect

Last Answer : (B) Decreases

During the constant rate period of drying of a solid, (A) Increased air humidity decreases the rate of drying (B) Increasing the air temperature decreases the drying rate (C) Surface evaporation of unbound moisture occurs (D) None of these

Description : During the constant rate period of drying of a solid, (A) Increased air humidity decreases the rate of drying (B) Increasing the air temperature decreases the drying rate (C) Surface evaporation of unbound moisture occurs (D) None of these

Last Answer : (C) Surface evaporation of unbound moisture occurs

For __________ drying, the effects of velocity, temperature and humidity of the gas and the thickness of the solid are the same. (A) Unsaturated surface (B) Constant rate (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : For __________ drying, the effects of velocity, temperature and humidity of the gas and the thickness of the solid are the same. (A) Unsaturated surface (B) Constant rate (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant (A) Humidity (B) Velocity (C) Temperature (D) All (A), (B) & (C)

Description : Drying of a wet solid under constant drying conditions means the exposure of the wet solid to the air of constant (A) Humidity (B) Velocity (C) Temperature (D) All (A), (B) & (C)

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

To avoid an interruption in the flow of a siphon, an air vessel is provided (A) At the inlet (B) At the outlet (C) At the summit (D) At any point between inlet and outle

Description : To avoid an interruption in the flow of a siphon, an air vessel is provided (A) At the inlet (B) At the outlet (C) At the summit (D) At any point between inlet and outle

Last Answer : Answer: Option C

Momentum correction factor used in fluid flow problems accounts for the (A) Change in direction of flow (B) Change in total energy (C) Change in pressure (D) Non uniform direction of velocities at inlet & outlet sections

Description : Momentum correction factor used in fluid flow problems accounts for the (A) Change in direction of flow (B) Change in total energy (C) Change in pressure (D) Non uniform direction of velocities at inlet & outlet sections

Last Answer : (D) Non uniform direction of velocities at inlet & outlet sections

During constant rate period, the rate of drying decreases with the (A) Decrease in air temperature (B) Increase in air humidity (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : During constant rate period, the rate of drying decreases with the (A) Decrease in air temperature (B) Increase in air humidity (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Conversion of dynamic velocity head into static pressure head in a centrifugal pump is the result of : (a) Increasing area of flow between adjacent vanes from inlet to outlet (b) Difference in pressure between suction and delivery ends (c) Radial thrust in pumps (d) Stuffing Box

Description : Conversion of dynamic velocity head into static pressure head in a centrifugal pump is the result of : (a) Increasing area of flow between adjacent vanes from inlet to outlet (b) Difference in pressure between suction and delivery ends (c) Radial thrust in pumps (d) Stuffing Box

Last Answer : (b) Difference in pressure between suction and delivery ends

The drying time between fixed moisture content within diffusion controlled 'falling rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid). (A) √T (B) T (C) T 2 (D) T

Description : The drying time between fixed moisture content within diffusion controlled 'falling rate period' is proportional to (assuming that drying occurs from all surfaces of the solid) (where, T = thickness of the solid). (A) √T (B) T (C) T 2 (D) T

Last Answer : (C) T

Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the flooding velocity, generally (C) 'Elution' means the desorption of the adsorbed solute by a solvent (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Description : Pick out the wrong statement: (A) Change in barometric pressure does not affect the relative humidity (B) In case of a packed tower, the operating velocity is about half of the ... (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

Last Answer : (D) The equilibrium moisture content of the solid can be reduced by increasing the absolute humidity

In a 1-1 concurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is (A) ∞ (B) 0 (C) Equal to the difference between hot and cold fluids inlet temperature (D) Equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature

Description : In a 1-1 concurrent heat exchanger, if the tube side fluid outlet temperature is equal to the shell side fluid outlet temperature, then the LMTD is (A) ∞ (B) 0 ... temperature (D) Equal to the difference between hot fluid inlet temperature and cold fluid outlet temperature

Last Answer : (B) 0

Can a cooling tower cool water below the wet bulb temperature of inlet air? (A) Yes (B) No (C) Yes; but height of cooling tower will be prohibitively high (D) Yes; but the air flow rate should be excessively high

Description : Can a cooling tower cool water below the wet bulb temperature of inlet air? (A) Yes (B) No (C) Yes; but height of cooling tower will be prohibitively high (D) Yes; but the air flow rate should be excessively high

Last Answer : (B) No

Which one of the following is true to estimate the range of cooling tower? a) Range = cooling water inlet temperature – wet bulb temperature b) Range = cooling water outlet temperature – wet bulb temperature c) Range = heat load in kcal per hour / water circulation in lines per hour d) None of the above

Description : Which one of the following is true to estimate the range of cooling tower? a) Range = cooling water inlet temperature - wet bulb temperature b) Range = cooling water outlet temperature - wet bulb temperature ... = heat load in kcal per hour / water circulation in lines per hour d) None of the above

Last Answer : Range = heat load in kcal per hour / water circulation in lines per hour

__________ of a material results, when its strength is increased & ductility is decreased by heating at a relatively lower temperature after cold working. (A) Solid solution hardening (B) Screw dislocation (C) Strain ageing (D) Twinning

Description : __________ of a material results, when its strength is increased & ductility is decreased by heating at a relatively lower temperature after cold working. (A) Solid solution hardening (B) Screw dislocation (C) Strain ageing (D) Twinning

Last Answer : (C) Strain ageing

During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains constant. (A) Wet bulb temperature (B) Partial pressure of water vapor (C) Relative humidity (D) None of these

Description : During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains ... pressure of water vapor (C) Relative humidity (D) None of these

Last Answer : (A) Wet bulb temperature

6. In a forward feed multiple effect, the pressure build up will be (A) Least at the inlet of the first effect (B) Least at the outlet of the last effect (C) Highest at the inlet of the last effect (D) Highest at the outlet of the last effect

Description : 6. In a forward feed multiple effect, the pressure build up will be (A) Least at the inlet of the first effect (B) Least at the outlet of the last effect (C) Highest at the inlet of the last effect (D) Highest at the outlet of the last effect

Last Answer : (B) Least at the outlet of the last effect

Cavitation in a centrifugal pump can be avoided by keeping the (A) Inlet pressure high (B) Outlet pressure low (C) Inlet pressure low (D) Outlet pressure high

Description : Cavitation in a centrifugal pump can be avoided by keeping the (A) Inlet pressure high (B) Outlet pressure low (C) Inlet pressure low (D) Outlet pressure high

Last Answer : (A) Inlet pressure high

The blades of a centrifugal impeller are said to be curved forward, if the __________ of the motion of impeller blades. (A) Inlet tip of a blade curves in a direction opposite to that (B) Outlet tip of a blade curves in a direction opposite to that (C) Inlet tip of a blade is towards the direction (D) Outlet tip of a blade is towards the direction

Description : The blades of a centrifugal impeller are said to be curved forward, if the __________ of the motion of impeller blades. (A) Inlet tip of a blade curves in a direction opposite to that (B) Outlet tip ... Inlet tip of a blade is towards the direction (D) Outlet tip of a blade is towards the direction

Last Answer : (D) Outlet tip of a blade is towards the direction

The 'E' curve for a non-ideal reactor defines the fraction of fluid having age between t and t + dt (A) At the inlet (B) At the outlet (C) In the reactor (D) Averaged over the inlet and outlet

Description : The 'E' curve for a non-ideal reactor defines the fraction of fluid having age between t and t + dt (A) At the inlet (B) At the outlet (C) In the reactor (D) Averaged over the inlet and outlet

Last Answer : (B) At the outlet

In case of parallel flow heat exchanger, the lowest temperature theoretically attainable by the hot fluid is __________ the outlet temperature of the cold fluid. (A) Equal to (B) More than (C) Less than (D) Either more or less than (depending upon the fluid)

Description : In case of parallel flow heat exchanger, the lowest temperature theoretically attainable by the hot fluid is __________ the outlet temperature of the cold fluid. (A) Equal to (B) More than (C) Less than (D) Either more or less than (depending upon the fluid)

Last Answer : (A) Equal to

Why is an electrical outlet called an outlet when you plug things into it? Shouldn't it be called an inlet?

Description : Why is an electrical outlet called an outlet when you plug things into it? Shouldn't it be called an inlet?

Last Answer : Current flow out from the wall socket when you plug a cord into it. If you want this to be called an inlet and not an outlet, then it would need to be reversed. When you plugged the cord ... flow is by a conductor such as your plug that trips the circuit and allows the electricity to flow freely.

A tank has two inlet pipes, A and B, which can fill the tank in 12 hours and 18 hours respectively, and an outlet C which can empty the tank in 9 hour

Description : A tank has two inlet pipes, A and B, which can fill the tank in 12 hours and 18 hours respectively, and an outlet C which can empty the tank in 9 hour

Last Answer : A tank has two inlet pipes, A and B, which can fill the tank in 12 hours and 18 hours ... time taken right from the start to fill the tank.

Which one of the following statements regarding septic tanks is wrong? A. A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided B. The outlet invert level is kept 5 to 7.5 cm below the inlet invert level C. The minimum width of septic level is 90 cm D. The depth of tank is kept equal to its width

Description : Which one of the following statements regarding septic tanks is wrong? A. A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided B. The outlet invert level is kept ... . The minimum width of septic level is 90 cm D. The depth of tank is kept equal to its width

Last Answer : ANS: D

State the function of the following parts in a heat engine: a) Crank shaft b) spark plug c) carburettord) kick starter e) inlet valve f) outlet valve

Description : State the function of the following parts in a heat engine: a) Crank shaft b) spark plug c) carburettord) kick starter e) inlet valve f) outlet valve

Last Answer : a) Crankshaft converts the linear movement of piston into circular motion. b) Spark plug is used in petrol engine to ignite the mixture of petrol and air in the cylinder. c) Carburettorhelps to mix ... -air or air into the cylinder. f) Outlet Valve allows the exhaust gases out of the cylinder.

In centrifugal pump installation, (A) Pump is properly primed before starting (B) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe (C) The motor may burn out if it is started with empty delivery pipe and with open gate valve (D) All the above

Description : In centrifugal pump installation,  (A) Pump is properly primed before starting  (B) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe  (C) The ... out if it is started with empty delivery pipe and with open gate valve  (D) All the above 

Last Answer : (D) All the above 

For attaining maximum efficiency, a Francis turbine runner is so designed as to result in radial discharge at exit. This is done by : a) Providing runner vane angle at inlet as 90o b) Providing guide vane angle at inlet as 90o c) Providing runner vane angle at exit as 90o d) Designing for absolute velocity at outlet to be inclined at 90o to direction of vane there

Description : For attaining maximum efficiency, a Francis turbine runner is so designed as to result in radial discharge at exit. This is done by : a) Providing runner vane angle at inlet as 90o b) Providing ... 90o d) Designing for absolute velocity at outlet to be inclined at 90o to direction of vane there

Last Answer : d) Designing for absolute velocity at outlet to be inclined at 90o to direction of vane there

Faucet A basically used as inlet pipe and Faucet B is used as outlet pipe. Faucet A and B both are opened simultaneously, all the time. When Faucet A fills the tank and Faucet B empty the tank, it will take thrice the time than when both the pipes fill the tank. When Faucet B is used for filling the tank, its efficiency remains constant. What is the ratio of efficiency of Faucet A and Faucet B respectively? a) 1:2 b) 2:1 c) 1:3 d) 3:1

Description : Faucet A basically used as inlet pipe and Faucet B is used as outlet pipe. Faucet A and B both are opened simultaneously, all the time. When Faucet A fills the tank and Faucet B empty the tank, it will take thrice the ... efficiency of Faucet A and Faucet B respectively? a) 1:2 b) 2:1 c) 1:3 d) 3:1

Last Answer : B Efficiency when both pipes used to fill = A + B And efficiency when Faucet A is used to fill and Faucet B is used to empty the tank = A-B So (A+B)/(A-B)=3/1 A/B+1/(A/B-1)=3/1 A/B+1=3(A/B-1) 3A/B-A/B=4 2A/B=4 A/B=2 Thus, the ratio of efficiency of Faucet A and B =2:1

24 pumps are connected to a tank. Some of them are inlet pumps and the others are outlet pumps. Each of the inlet pumps an fill the tank in 16hours and each of the outlet pumps can empty the tank completely in 12hours. If all the pumps are kept open, the empty tank gets filled in 48 hours. How many inlet pumps are there? A) 16 B) 18 C) 17 D) 14

Description : 24 pumps are connected to a tank. Some of them are inlet pumps and the others are outlet pumps. Each of the inlet pumps an fill the tank in 16hours and each of the outlet pumps can empty the tank completely in ... gets filled in 48 hours. How many inlet pumps are there? A) 16 B) 18 C) 17 D) 14

Last Answer : D (x/16)-[(24-x)/12] = 1/48 x/16-24/48+x/12=1/48 (3+4)x/48=97/48 7x/48=97/48 7x=97 X=14

Exposure to SO2 containing chimney gases results in the (A) Reduction in strength of leather & cloth (B) Acceleration of corrosion rates of metals (C) Increased drying & hardening time of paints (D) All (A), (B) and (C)

Description : Exposure to SO2 containing chimney gases results in the (A) Reduction in strength of leather & cloth (B) Acceleration of corrosion rates of metals (C) Increased drying & hardening time of paints (D) All (A), (B) and (C)

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

Pick out the wrong statement. (A) Cellulose acetate membranes are used in dialysis process (B) Elutriation process refers to when the soluble material is largely concentrated on the surface of an insoluble solid and is simply washed off by the solvent (C) 'Cascade' means a group of stages interconnected so that various streamflow from one to another(D) Zirconia probe is used for the humidity measurement

Description : Pick out the wrong statement. (A) Cellulose acetate membranes are used in dialysis process (B) Elutriation process refers to when the soluble material is largely concentrated on the surface of an ... that various streamflow from one to another (D) Zirconia probe is used for the humidity measurement

Last Answer : (D) Zirconia probe is used for the humidity measurement

For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) Decreases the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Description : For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) ... the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Last Answer : (C) Increases the overall heat transfer coefficient

When the __________ the relative humidity of air decreases, despite an increase in the absolute humidity. (A) Temperature rises (B) Pressure rises (C) Temperature falls (D) Pressure falls

Description : When the __________ the relative humidity of air decreases, despite an increase in the absolute humidity. (A) Temperature rises (B) Pressure rises (C) Temperature falls (D) Pressure falls

Last Answer : (A) Temperature rises

Air initially at 101. 3 kPa and 40°C and with a relative humidity of 50%, is cooled at constant pressure to 30°C. The cooled air has a (A) Higher dew point (B) Higher absolute (specific) humidity (C) Higher relative humidity (D) Higher wet bulb temperature

Description : Air initially at 101. 3 kPa and 40°C and with a relative humidity of 50%, is cooled at constant pressure to 30°C. The cooled air has a (A) Higher dew point (B) Higher absolute (specific) humidity (C) Higher relative humidity (D) Higher wet bulb temperature

Last Answer : (C) Higher relative humidity

The relative humidity of air decreases in-spite of an increase in the absolute humidity, when the (A) Temperature rises (B) Pressure rises (C) Temperature falls (D) Pressure falls

Description : The relative humidity of air decreases in-spite of an increase in the absolute humidity, when the (A) Temperature rises (B) Pressure rises (C) Temperature falls (D) Pressure falls

Last Answer : (A) Temperature rises

Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled (A) And humidified (B) And dehumidified with increase in wet bulb temperature (C) At the same relative humidity (D) And dehumidified with decrease in wet bulb temperature

Description : Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled (A) And ... (C) At the same relative humidity (D) And dehumidified with decrease in wet bulb temperature

Last Answer : (D) And dehumidified with decrease in wet bulb temperature

Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure to the air with a wet bulb temperature of 60°C, then both the approach & the range would be 10°C (C) For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature & adiabatic cooling lines are the same (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Description : Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure ... & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Last Answer : (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in terms of __________ humidity. (A) Molal (B) Relative (C) Percentage (D) None of these

Description : Humidity chart is useful for the solution of problems concerning condensation, vaporisation and air conditioning. At a given dry bulb temperature, value of humidity obtained from the humidity chart directly, is in ... (A) Molal (B) Relative (C) Percentage (D) None of these

Last Answer : (A) Mola

Which of the following can be calculated theoretically using steam table and Dalton's law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known? (A) Dew point (B) Humidity ratio (C) Wet bulb temperature (D) None of these

Description : Which of the following can be calculated theoretically using steam table and Dalton's law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known? (A) Dew point (B) Humidity ratio (C) Wet bulb temperature (D) None of these

Last Answer : (C) Wet bulb temperature

Which of the following processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C? (A) Humidification only (B) Heating only (C) Both heating and humidification (D) Evaporative cooling

Description : Which of the following processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C ... (B) Heating only (C) Both heating and humidification (D) Evaporative cooling

Last Answer : (C) Both heating and humidification

During sensible heating of humid air (A) Relative humidity increases (B) Dew point remains constant (C) Dry bulb & wet bulb temperature increases (D) Both 'b' & 'c'

Description : During sensible heating of humid air (A) Relative humidity increases (B) Dew point remains constant (C) Dry bulb & wet bulb temperature increases (D) Both 'b' & 'c'

Last Answer : (D) Both 'b' & 'c'

Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs? (A) Enthalpy (B) Relative humidity (C) Wet bulb temperature (D) Dew point temperature

Description : Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs? (A) Enthalpy (B) Relative humidity (C) Wet bulb temperature (D) Dew point temperature

Last Answer : (D) Dew point temperature

At 100% relative humidity, the dew point temperature of moist air is (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) Equal to the wet bulb temperature (D) Equal to the ambient temperature

Description : At 100% relative humidity, the dew point temperature of moist air is (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) Equal to the wet bulb temperature (D) Equal to the ambient temperature

Last Answer : (B) More than the wet bulb temperature

The wet bulb temperature is lower in dry air than in wet air at the same temperature. A dry bulb thermometer registers a higher temperature than a wet bulb thermometer except at __________ percent relative humidity. (A) 0 (B) 100 (C) 50 (D) None of these

Description : The wet bulb temperature is lower in dry air than in wet air at the same temperature. A dry bulb thermometer registers a higher temperature than a wet bulb thermometer except at __________ percent relative humidity. (A) 0 (B) 100 (C) 50 (D) None of these

Last Answer : Option B

The dew point of moist air becomes __________ with decrease in its relative humidity. (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) More than the dry bulb temperature (D) Equal to wet bulb temperature

Description : The dew point of moist air becomes __________ with decrease in its relative humidity. (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) More than the dry bulb temperature (D) Equal to wet bulb temperature

Last Answer : Option A

__________ remains constant during the adiabatic cooling of moist air. (A) Wet bulb temperature (B) Dry bulb temperature (C) Relative humidity (D) Specific humidity

Description : __________ remains constant during the adiabatic cooling of moist air. (A) Wet bulb temperature (B) Dry bulb temperature (C) Relative humidity (D) Specific humidity

Last Answer : Option A

The dew point temperature lines on psychrometric charts are straight inclined sloping downwards to the right. When relative humidity of moist air is 100%, then (A) Wet bulb temperature=dry bulb temperature (B) Wet bulb temperature=dew point temperature (C) Saturation temperature=dew point temperature (D) All 'a', 'b' & 'c

Description : The dew point temperature lines on psychrometric charts are straight inclined sloping downwards to the right. When relative humidity of moist air is 100%, then (A) Wet bulb temperature=dry bulb temperature (B) ... temperature (C) Saturation temperature=dew point temperature (D) All 'a', 'b' & 'c

Last Answer : Option D