Description : Pick out the wrong statement. (A) Recycled coarse material to the grinder by a classifier is termed as circulating load (B) Wear and tear in wet crushing is more than that in dry crushing of ... a pipeline which permits the solids to settle down due to reduction in velocity of the dust laden gas
Last Answer : (C) Size enlargement (opposite of size reduction) is not a mechanical operation
Description : Actual operating speed of a ball mill may vary from 65 to 80% of the critical speed. Which of the following duties would require the ball mill to be operated at maximum percentage of critical speed? (A) ... of large particles (upto 1.25 cms) (D) Dry grinding of large particles in un-baffed mills
Last Answer : (D) Dry grinding of large particles in un-baffed mills
Description : Pick out the wrong statement: (A) Magnetic separation method can be employed to treat both dry & wet ores (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed ... ) Gyratory crusher is used for coarse crushing (D) Screens are of stationary, moving and vibratory types
Last Answer : (B) Reduction ratio in crushing operation is defined as the ratio of minimum feed size to the maximum product size
Description : In case of a pipe of constant cross-sectional area, the maximum fluid velocity obtainable is (A) The velocity of sound (B) Dependent on its cross-sectional area (C) Dependent on fluid viscosity (D) Dependent on fluid density
Last Answer : (A) The velocity of sound
Description : The ratio of average fluid velocity to the maximum velocity in case of laminar flow of a Newtonian fluid in a circular pipe is (A) 0.5 (B) 1 (C) 2 (D) 0.66
Last Answer : (A) 0.5
Description : Pick out the wrong statement pertaining to fluid flow. (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5 (B) The Newtonian ... at the centre of the pipe (C) Navier-Stokes equation is applicable to the analysis of viscous flows
Last Answer : (A) The ratio of average velocity to the maximum velocity for turbulent flow of Newtonian fluid in circular pipes is 0.5
Description : Hydraulic mean depth (Dm) for a circular pipe of diameter 'D' flowing full is 0.25 D. For a circular channel, at Dm = 0.3 D, gives the condition for the maximum (A) Flow rate (B) Mean velocity (C) Both 'a' & 'b' (D) Neither 'a' nor 'b
Last Answer : (B) Mean velocity
Description : Pick out the wrong statement: (A) Greater is the kinematic viscosity of the liquid, greater is the thickness of the boundary layer (B) Blowers develop a maximum pressure of 2 atmospheres ( ... factor in case of turbulent flow of liquids in pipe depends upon relative roughness & Reynolds number
Last Answer : (C) Friction losses in pipe fittings are generally expressed in terms of velocity heads
Description : In case of turbulent flow of a Newtonian fluid in a straight pipe, the maximum velocity is equal to (where, Vavg = average fluid velocity) (A) Vavg (B) 1.2 Vavg (C) 1.5 Vavg (D) 1.8 Vavg
Last Answer : (B) 1.2 Vavg
Description : For turbulent flow of Newtonian fluid in a circular cross-section pipe, the ratio of maximum to average fluid velocity is (A) 0.5 (B) 1 (C) 0.66 (D) < 0.5
Last Answer : (B) 1
Description : . In case of turbulent flow of fluid through a circular pipe, the (A) Mean flow velocity is about 0.5 times the maximum velocity (B) Velocity profile becomes flatter and flatter with ... , shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Last Answer : (D) Skin friction drag, shear stresses, random orientation of fluid particles and slope of velocity profile at the wall are more
Description : What is the maximum recommended velocity for steam in a plant pipe network?
Last Answer : High-pressure steam should be limited to about 150 ft/s and low-pressure steam should be limited to about 100 ft/s.
Description : Explain the following a) Dry Bulb Temperature and Wet bulb Temperature b) Maximum Demand and Power Factor c) Gross Calorific Value & Net Calorific Value d) 5S & Return of Investment (ROI) e) CUSUM
Last Answer : a) Dry Bulb Temperature and Wet bulb Temperature Dry bulb Temperature is an indication of the sensible heat content of air-water vapour mixtures Wet bulb Temperature is a measure of ... of capital cost. This is a broad indicator of the annual return expected from initial capital investment
Description : At the center line of a pipe flowing under pressure where the velocity gradient is zero, the shear stress will be (A) Minimum (B) Maximum (C) Zero (D) Could be any value
Last Answer : Answer: Option D
Description : When a liquid is flowing through a pipe, the velocity of the liquid is (A) Maximum at the centre and minimum near the walls (B) Minimum at the centre and maximum near the walls (C) Zero at the centre and maximum near the walls (D) Maximum at the centre and zero near the walls
Last Answer : Answer: Option A
Description : Consider the following statements in respect of steady laminar flow through a circular pipe: 1. Shear stress is zero on the central axis of the pipe 2. Discharge varies directly with the viscosity of the fluid 3. Velocity is maximum at the ... 2 , 3 & 4 (b) 1 & 3 only (c) 2 & 4 only (d)3 & 4 only
Last Answer : (b) 1 & 3 only
Description : Identification of pipelines carrying different liquids and gases is done by the __________ of the pipe. (A) Diameter (B) Colour (C) Altitude (D) None of these
Last Answer : (B) Colour
Description : Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of __________ will facilitate the most accurate measurement of the temperature. (A) Copper (B) Steel (C) Aluminium (D) Brass
Last Answer : Option A
Description : Wet steam at 1 MPa flowing through a pipe is throttled to a pressure of 0.1 MPa. If the throttling temperature is110°C, What is the quality of the steam in the pipe? a) 96% b) 86% c) 76% d) 66%
Last Answer : 96%
Description : Rio Summit is associated with – (1) Convention on Biological Diversity (2) Green house gases (3) Ozone depletion (4) Wet lands
Last Answer : (1) Convention on Biological Diversity Explanation: The United Nations Conference on Environment and Development (UNCED), otherwise known as the Earth Summit or Rio Summit, was held in Rio de Janeiro, ... for signature at the Rio Summiton 5 June 1992 and entered into force on 29 December 1993.
Description : Rio Summit is associated with (1) Convention on Biological Diversity (2) Green house gases (3) Ozone depletion (4) Wet lands
Last Answer : Convention on Biological Diversity
Description : The cooling effect in a cooling tower cannot be increased by (A) Increasing the air velocity over the wet surfaces (B) Reducing the humidity of entering air (C) Lowering the barometric pressure (D) None of these
Last Answer : (D) None of these
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)
Description : The cooling effect in a cooling tower can be speeded up by (A) Increasing the air velocity and area of exposed wet surface (B) Reducing the barometric pressure (C) Reducing the humidity of the air (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : Natural gas recovered along with crude oil from oil wells is called wet natural gas which has a higher __________ compared to the dry natural gas. (A) Unsaturated hydrocarbon content (B) Calorific value (C) Quantity of propane (D) Quantity of butane
Last Answer : (B) Calorific value
Description : In case of grinding in a ball mill (A) Wet grinding achieves a finer product size than dry grinding (B) Its capacity decreases with increasing fineness of the products (C) Grinding cost and power requirement increases with increasing fineness of the products (D) All (A), (B) and (C)
Description : Wet grinding in a revolving mill __________ as compared to dry grinding. (A) Gives less wear on chamber walls (B) Requires more energy (C) Increases capacity (D) Complicates handling of the product
Last Answer : (C) Increases capacity
Description : Use of 'grinding aids' is done in __________ grinding. (A) Dry (B) Wet (C) Ultrafine (D) Intermediate
Last Answer : (A) Dry
Description : In case of a revolving mill, wet grinding compared to dry grinding (A) Requires more energy (B) Has less capacity (C) Complicates handling & classification of the product (D) None of these
Description : Work index is the gross energy (kWh/tonne of feed) necessary to reduce a very large feed to such a size that 80% of product particles will pass through a 0.1 mm screen. The value of work index determined for wet grinding should ... to get the same for dry grinding. (A) 1.0 (B) 0.5 (C) 1.34 (D) 4.34
Last Answer : (C) 1.34
Description : Wood is corroded by (A) Hydrochloric acid (B) SO2 (dry or wet) (C) Chlorine (dry or wet) (D) All (A), (B) and (C)
Description : Which of the following material of construction may be recommended by a chemical engineer for handling a gaseous chlorine (dry or wet) stream in a fluid flow system? (A) High silicon iron, silicon rubber ... Mild steel and stainless steel (C) Cast iron, tin and aluminium (D) Copper, nickel and Monel
Last Answer : (A) High silicon iron, silicon rubber, Kel-F and Teflon
Description : Glass is corroded by (A) Fluorine (dry or wet) (B) Sulphuric acid (C) Phosphoric acid (D) None of these
Last Answer : (A) Fluorine (dry or wet)
Description : __________ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid. (A) Dew point (B) Bubble point (C) Dry bulb temperature (D) Wet bulb temperature
Last Answer : (A) Dew point
Description : Which of the following parameters remains almost constant during adiabatic saturation of unsaturated air? (A) Dry bulb temperature (B) Dew point (C) Wet bulb temperature (D) None of these
Last Answer : (C) Wet bulb temperature
Description : Dry bulb temperature of unsaturated air is more than its __________ temperature. (A) Dew point (B) Wet bulb (C) Both 'a' & 'b' (D) Neither 'a' nor 'b
Last Answer : (C) Both 'a' & 'b
Description : __________ temperature is the steady state temperature attained by a small amount of liquid evaporating into a large quantity of unsaturated gasvapor mixture. (A) Dry bulb (B) Wet bulb (C) Dew point (D) None of these
Last Answer : (B) Wet bulb
Description : If moisture content of solid on dry basis is X, then the same on wet basis is (A) X/(X + 1) (B) X/(1 - X) (C) (1 + X)/X (D) (1 - X)/X
Last Answer : (A) X/(X + 1)
Description : The temperature to which a vapour gas mixture must be cooled (at varying humidity) to become saturated is called the __________ temperature. (A) Dew point (B) Wet bulb (C) Dry bulb (D) None of these
Description : Unsaturated air (with dry bulb and wet bulb temperatures being 45°C and 25°C respectively) is passed through a water spray chamber maintained at 23°C. The air will be cooled and (A) ... temperature decreasing B) Humidified at constant wet bulb temperature (C) Dehumidified (D) None of these
Last Answer : (A) Humidified with wet bulb temperature decreasing
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
Description : Dry bulb temperature of the gas is __________ the wet bulb temperature. (A) Less than (B) More than (C) Equal to (D) None of these
Last Answer : (B) More than
Description : Wet bulb and dry bulb temperatures becomes identical at __________ percent saturation curve. (A) 100 (B) 50 (C) 78 (D) None of these
Last Answer : (A) 100
Description : It takes 6 hours to dry a wet solid from 50% moisture content to the critical moisture content of 15%. How much longer it will take to dry the solid to 10% moisture content, under the same drying conditions? (The ... 5%). (A) 15 min (B) 51 min (C) 71 min (D) 94 min
Last Answer : (C) 71 min
Description : The temperature of water cooled in cooling tower is always __________ temperature of entering air. (A) More than the wet bulb (B) Less than the wet bulb (C) Equal to the wet bulb (D) Equal to the dry bulb
Last Answer : (A) More than the wet bulb
Description : In case of unsaturated air (A) Dew point < wet bulb temperature (B) Wet bulb temperature < dry bulb temperature (C) Both (A) and (B) (D) Neither (A) not (B)
Last Answer : (C) Both (A) and (B)
Description : Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called the __________ temperature. (A) Dry-bulb (B) Wet-bulb (C) Dew point (D) Adiabatic saturation
Last Answer : (B) Wet-bulb
Description : The wet and 'dry bulb temperature for a vapour-gas mixture are 25°C and 30°C respectively. If the mixture is heated to 45°C at constant pressure, the wet bulb temperature will be __________ °C. (A) 25 (B) > 25 (C) < 25 (D) - 25
Last Answer : (B) > 25
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