MCQOPTIONS
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MCQOPTIONS
This section includes 97 Mcqs, each offering curated multiple-choice questions to sharpen your Chemical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Scaling occurs in boiler tubes due to the fact that, the solubility of Ca(OH) 2 __________ with increasing temperature. |
| A. | increases |
| B. | decreases |
| C. | shows inversion of solubility |
| D. | none of these |
| Answer» B. decreases | |
| 52. |
The Al 2 O 3 content of cryolite in Hall-Heroult's cell is maintained between __________ percent. |
| A. | 2-5 |
| B. | 18-20 |
| C. | 12-15 |
| D. | 6-12 |
| Answer» B. 18-20 | |
| 53. |
A boy weighing 110 lb climbs up a 50 ft high vertical destination in 100 seconds. Horse power of the boy is __________ hp. |
| A. | 0.1 |
| B. | 0.5 |
| C. | 0.8 |
| D. | 1 |
| Answer» B. 0.5 | |
| 54. |
Theoretical volume of oxygen required for complete combustion of 1Nm 3 of acetylene, in oxy-acetylene welding is __________ Nm 3 . |
| A. | 0.5 |
| B. | 1 |
| C. | 2 |
| D. | 2.5 |
| Answer» E. | |
| 55. |
High speed steel tools retain their hardness upto a temperature of __________ °C. |
| A. | 500 |
| B. | 750 |
| C. | 900 |
| D. | 1100 |
| Answer» D. 1100 | |
| 56. |
The hydraulic radius of a circular pipe of diameter ' d ' flowing full is |
| A. | d /4 |
| B. | d /2 |
| C. | 2 d /3 |
| D. | d /3 |
| Answer» B. d /2 | |
| 57. |
F e O (s) + CO (g) = Fe (s) + CO 2 (g), k = 0. 435 at 1173E; At equilibrium, what will be the number of moles of CO gas required to reduce one mole of F e O at 1173 K? |
| A. | 1.0 |
| B. | 1.3 |
| C. | 2.3 |
| D. | 3.3 |
| Answer» E. | |
| 58. |
Eutectic reaction for iron-carbon system occurs at a temperature of __________ °C. |
| A. | 723 |
| B. | 959 |
| C. | 1147 |
| D. | 1493 |
| Answer» B. 959 | |
| 59. |
In Newton's law of viscosity, which states that the shear stress is proportional to the __________ Co-efficient of viscosity is called dynamic or absolute viscosity(where, V = velocity, V g = velocity gradient ). |
| A. | V 2 |
| B. | 1/ V 2 |
| C. | 1/ V g |
| D. | V g |
| Answer» E. | |
| 60. |
Percentage of differential pressure lost in a venturimeter with a tapering of 15° may be about |
| A. | 1 |
| B. | 10 |
| C. | 25 |
| D. | 50 |
| Answer» C. 25 | |
| 61. |
The refractory brick which has good thermal shock resistance at high temperature but cracks on cooling below 400°C is |
| A. | magnesite |
| B. | chrome |
| C. | silica |
| D. | fireclay |
| Answer» D. fireclay | |
| 62. |
Work done by a/an __________ process is determined by . |
| A. | adiabatic |
| B. | quasi-static |
| C. | isothermal |
| D. | isentropic |
| Answer» C. isothermal | |
| 63. |
Melting point & boiling points of liquid oxygen are respectively - 218.8°C & - 183°C, while the same for liquid nitrogen is - 210°C & - 195.8°C respectively. The difference in melting points of liquid oxygen & liquid nitrogen is not equal to 8.8 |
| A. | °C |
| B. | °F |
| C. | °K |
| D. | °R |
| Answer» C. °K | |
| 64. |
End cooler' or 'after cooler' is employed in air compressor mainly to |
| A. | remove oil vapour or moisture from air. |
| B. | cool the dry air before use. |
| C. | reduce the volumetric capacity of receiver. |
| D. | none of these. |
| Answer» B. cool the dry air before use. | |
| 65. |
The heat released by cooling one mole of copper from 400 K to room temperature (300 K) is (assume : C p of copper is 23 J K -1 mole -1 ) |
| A. | 2300 J |
| B. | 4600 J |
| C. | 230 J |
| D. | 2.3 x 10 6 J |
| Answer» B. 4600 J | |
| 66. |
Eutectoid reaction for iron-carbon system occurs at a temperature of __________ °C. |
| A. | 597 |
| B. | 959 |
| C. | 1147 |
| D. | 1493 |
| Answer» E. | |
| 67. |
Boiling temperature of carbon dioxide at atmospheric pressure is __________ °C. |
| A. | -30.5 |
| B. | -78.5 |
| C. | -183.5 |
| D. | -10.5 |
| Answer» C. -183.5 | |
| 68. |
Out of the following substances, one ton of __________ will store the maximum heat for a rise of 30°C in temperature. |
| A. | steel |
| B. | lignite |
| C. | water |
| D. | lime stone |
| Answer» D. lime stone | |
| 69. |
In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the |
| A. | range is 15°F. |
| B. | approach is 10°F. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 70. |
GASOHOL' widely used in Brazil as a motor fuel is a mixture of alcohol and |
| A. | petrol. |
| B. | LPG. |
| C. | light hydrocarbon gases (e.g. butane or propane). |
| D. | none of these. |
| Answer» B. LPG. | |
| 71. |
Hot extrusion of aluminium is done in the temperature range of __________ °C. |
| A. | 550-600 |
| B. | 450-500 |
| C. | 350-400 |
| D. | 250-300 |
| Answer» D. 250-300 | |
| 72. |
The approximate height of a blast furnace having a useful volume of 2000 m 3 is about __________ metres |
| A. | 25 |
| B. | 35 |
| C. | 55 |
| D. | 75 |
| Answer» D. 75 | |
| 73. |
Volumetric composition of flue gas analysed with the Orsat apparatus is : CO 2 = 12%, O 2 = 8%, CO = nil, N 2 = 80%. This flue gas composition indicates that |
| A. | pure oxygen has been used for combustion. |
| B. | nitrogen percentage in the fuel is very high. |
| C. | excess air has been used for combustion. |
| D. | hydrogen is not present in the fuel. |
| Answer» D. hydrogen is not present in the fuel. | |
| 74. |
A 2 kg object weighs 1.8 kgf on a spring balance. The value of 'g' at that location in m/sec 2 is |
| A. | 8.82 |
| B. | 9.81 |
| C. | 10.88 |
| D. | 0.95 |
| Answer» B. 9.81 | |
| 75. |
Temperature attained in soldering of metals is about __________ °C. |
| A. | 150-300 |
| B. | 400-500 |
| C. | 650-800 |
| D. | 1000-1100 |
| Answer» B. 400-500 | |
| 76. |
The efficiency of a Carnot heat engine operating between absolute temperatures T 1 and T 2 (when, T 1 > T 2 ) is given by ( T 1 - T 2 )/ T 1 . The co-efficient of performance (CO.P.) of a Carnot heat pump operating between T 1 and T 2 is given by |
| A. | T 1 /( T 1 - T 2 ) |
| B. | T 2 /( T 1 - T 2 ) |
| C. | T 1 / T 2 |
| D. | T 2 / T 1 |
| Answer» C. T 1 / T 2 | |
| 77. |
In a furnace with heating element temperature at 1700°C, the dominant machanism of heat transfer will be |
| A. | conduction |
| B. | radiation |
| C. | natural convection |
| D. | forced convection |
| Answer» C. natural convection | |
| 78. |
Heat required to raise the temperature of a body by 1 °C is called its |
| A. | heat capacity. |
| B. | specific heat capacity. |
| C. | thermal conductivity. |
| D. | water equivalent. |
| Answer» B. specific heat capacity. | |
| 79. |
Flare tower' used in industry is meant for |
| A. | venting off (after burning) the excess inflammable/toxic gases at high pressure. |
| B. | absorbing the pollutant gases from the furnace exhaust. |
| C. | cooling of furnace exhaust gases. |
| D. | none of these. |
| Answer» B. absorbing the pollutant gases from the furnace exhaust. | |
| 80. |
Electrolytic reduction cell used for conversion of calcined Al 2 O 3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to |
| A. | achieve very high purity of aluminium (99.9%). |
| B. | keep the electrolyte in liquid condition by the generation of heat. |
| C. | electrolytically dissociate alumina. |
| D. | both(b) & (c). |
| Answer» E. | |
| 81. |
Which of the following has the highest modulus of elasticity (about 7 x 10 6 kg/cm 2 ) ? |
| A. | High speed steel |
| B. | Stainless steel |
| C. | Tungsten carbide |
| D. | Superalloys |
| Answer» D. Superalloys | |
| 82. |
The concentration of (H + ) ions is 4 x 10 -5 in a solution. Then pH of the solution will be (Given log 4 = 0.6 ) |
| A. | 4.4 |
| B. | 5.6 |
| C. | 8.4 |
| D. | 2.4 |
| Answer» B. 5.6 | |
| 83. |
Austempering of steel requires.it to be heated to 875°C followed by sudden cooling to 250-525°C, thereby changing austenite to |
| A. | sorbite |
| B. | bainite |
| C. | martensite |
| D. | troostite |
| Answer» C. martensite | |
| 84. |
For efficient performance of a blast furnace, the extent of reduction of Wustite (F e O) should be |
| A. | 100% indirect reduction. |
| B. | 100% direct reduction. |
| C. | 50-60% indirect reduction. |
| D. | 30-40% indirect reduction. |
| Answer» D. 30-40% indirect reduction. | |
| 85. |
A fire tube boiler is limited to a maximum steam pressure of about __________ kg/cm 2 . |
| A. | 6 |
| B. | 18 |
| C. | 38 |
| D. | 52 |
| Answer» C. 38 | |
| 86. |
The emf of a Deniell cell can be increased by |
| A. | decreasing the surface area of the electrodes. |
| B. | increasing the concentration of zinc sulphate solution. |
| C. | increasing the surface area of the electrodes. |
| D. | increasing the concentration of copper sulphate solution. |
| Answer» E. | |
| 87. |
In a counter flow heat exchanger, hot fluid enters at 170°C & leaves at 150°C, while the cold fluid enters at 50°C & leaves at 70°C. The arithmetic mean temperature difference in this case is __________ °C. |
| A. | 20 |
| B. | 60 |
| C. | 120 |
| D. | ? |
| Answer» E. | |
| 88. |
The temperature at which the magnetic property of iron disappears (i.e., it becomes non-magnetic) and its electrical conductivity & specific heat also changes, is called the 'Curie point', which is __________ °C. |
| A. | 768 |
| B. | 908 |
| C. | 1400 |
| D. | 1539 |
| Answer» B. 908 | |
| 89. |
Co-efficient of performance of a Carnot cycle refrigerator operating between - 23°C and + 27°C is |
| A. | 3 |
| B. | 5 |
| C. | 0.5 |
| D. | 1.5 |
| Answer» C. 0.5 | |
| 90. |
Super conduction in metals is observed at a temperature of __________ °K. |
| A. | <100 |
| B. | >100 |
| C. | about 273 |
| D. | about 373 |
| Answer» C. about 273 | |
| 91. |
The activity of pure hydrogen gas at 1000°C and 5 atm pressure |
| A. | is always less than 1. |
| B. | is always greater than 1. |
| C. | can be 5. |
| D. | depends on the choice of the standard state. |
| Answer» E. | |
| 92. |
Regeneration of molecular seive requires it to be heated to a temperature of about __________ °C. |
| A. | 80-120 |
| B. | 200-300 |
| C. | 600-800 |
| D. | 1000-1100 |
| Answer» E. | |
| 93. |
The transition temperature at which all the ferromagnetic materials become paramagnetic materials is termed as the 'Curie temperature'. Its value for cobalt is __________ °C. |
| A. | 768 |
| B. | 1127 |
| C. | 1359 |
| D. | 1480 |
| Answer» C. 1359 | |
| 94. |
M 10 index of coke indicates its |
| A. | compressive strength. |
| B. | hardness. |
| C. | abrasion resistance. |
| D. | impact strength. |
| Answer» D. impact strength. | |
| 95. |
The boiling & freezing points on a newly defined temperature scale in degree 'D' are 400°D & 100°D respectively. The temperature reading corresponding to 60°C on this new temperature scale will be equal to __________ °D. |
| A. | 140 |
| B. | 180 |
| C. | 240 |
| D. | 280 |
| Answer» E. | |
| 96. |
Consider the equilibrium A ( g ) + B ( g ) = AB ( g ) . When the partial pressure of A is 10 -2 atm, the partial pressure of B is 10 -3 atm and the partial pressure of AB is 1 atm, the equilibrium constant 'K' is |
| A. | 10 atm -1 |
| B. | 10 5 atm -1 |
| C. | 10 (dimensionless) |
| D. | 10 5 (dimensionless) |
| Answer» C. 10 (dimensionless) | |
| 97. |
Nusselt number is related to Grashoff number ( Gr ) in turbulent & laminar flow respectively, in respect of free convection over a vertical flat plate as |
| A. | Gr 0.25 , Gr |
| B. | Gr 0.25 , Gr 0.33 |
| C. | Gr , Gr 0.25 |
| D. | Gr 0.33 , Gr 0.25 |
| Answer» B. Gr 0.25 , Gr 0.33 | |