chemical engineering Mcqs
101. Co-efficient of performance of a Carnot cycle refrigerator operating between 23C and + 27C is ________________?
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A. 0.5

B. 3

C. 1.5

D. 5
102. ________________ is a special constituent of chlorophyll without which photosynthesis is not possible ?
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A. Nitrogen

B. Calcium

C. Phosphorous

D. Hydrogen

103. Boiler tube size is specified by its thickness and _____________________ diameter ?
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A. Outside

B. Inside

C. None of these

D. Mean

104. The escape velocity of a body on earth which is independent of its mass is about ______________________ km/second?
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A. 11

B. 3

C. 15

D. 7

105. Percentage of differential pressure lost in a Venturimeter with a tapering of 15 may be about___________________?
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A. 25

B. 10

C. 50

D. 1

106. Air-petrol ratio for maximum power generation in spark ignition engine is about_____________________?
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A. 12 : 1

B. 24:01:00

C. 6:01

D. 18:01

107. Temper brittleness of a material can be fairly detected by the ________________ test ?
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A. Fatigue

B. Tensile

C. Notched bar impact

D. Hardness

108. With increase in temperature, the electrical conductivity of semiconductors_____________________?
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A. Increases

B. Decreases

C. Remain constant

D. Either A. or B. depends on the type of semi-conductor

109. Materials having ________________ lattice structure are usually the most ductile ?
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A. Body centred cubic (bcc)

B. Face centred cubic (fcc)

C. None of these

D. Hexagonal close packed (hcp)

110. The refractory lining of the bottom in a basic electric arc furnace is made of___________________?
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A. Silica

B. Alumina

C. Magnesia

D. Fireclay

111. Catalyst used in the catalytic converter employed in automobile exhaust line for complete combustion/oxidation of carbon monoxide, nitrogen oxides and hydrocarbons is__________________?
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A. Alumina

B. Platinum

C. Vanadium pentoxide

D. Iron oxide

112. Lap joints are preferred over butt joints in soldering/brazing, because these joints are _________________?
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A. Weaker in tension but stronger in shear

B. Weaker in shear but stronger in tension

C. Stronger in both shear and tension

D. The lap joints are easily made
113. Annealing of cast iron__________________?
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A. None of these

B. Decreases the free carbon

C. Softens it to facilitate machining

D. Increases the strength

114. The pressure outside a bubble/droplet of liquid is ________________ the internal pressure?
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A. Greater than

B. Equal to

C. Less than

D. Unpredictable; depends on the bubble size

115. Water flow in the river during flood can be categorized as the _________________ flow ?
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A. Steady uniform

B. Steady non-uniform

C. Unsteady non-uniform

D. Unsteady uniform

116. 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 ?
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A. None of these

B. 0

C. 100

D. 50

117. A steam carrying pipeline is insulated with two layers of insulating materials with the inferior insulation material forming the inner part. If the two insulating layers are interchanged, the heat conducted will____________________?
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A. Decrease

B. May increase or decrease; depends on the thickness of each layer

C. Increase

D. Remain unaffected
118. Which of the following is the most suitable material of construction for the condenser tubes, where the cooling medium is brine (salty water) ?
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A. Copper

B. Titanium

C. Aluminium

D. Stainless steel

119. 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____________________?
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A. 10 atm-1

B. 10 (dimensionless)

C. 105 (dimensionless)

D. 105 atm-1
120. Sub zero treatment of steel is done to____________________?
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A. Enhance its working performance in sub zero atmosphere

B. Induce temper brittleness after its hardening

C. Suppress martensite transformation

D. Reduce the retained austenite in hardened steel
121. Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of _______________ gms of zinc per m2 of steel strip ?
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A. 1000-1500

B. 10-May

C. 120-500

D. 1500-3000

122. Propulsion of rocket follows from the_________________?
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A. Newtons second law of motion

B. Archimedes principle

C. Newtons third law of motion

D. Law of projectiles

123. The _________________ of a double acting reciprocating pump as compared to the single acting pump will be almost double ?
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A. Overall efficiency

B. Flow output

C. Head developed

D. Weight

124. Thermistors are used in _____________ devices?
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A. Voltage measuring

B. Temperature measuring

C. Temperature compensating

D. Both B. & C.
125. Plastics as a material of construction suffer from the drawback of low_________________?
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A. Machinability

B. Strength

C. Plastic deformation

D. Density

126. Fire in fuel gas pipelines is extinguished most effectively by _________________?
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A. Blanketting the area with nitrogen atmosphere

B. Spraying water

C. None of these

D. Fire fighting foam

127. With increase in annealing temperature, the following defect density decreases?
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A. All of these

B. Vacancy

C. Grain boundary

D. Dislocation

128. Shampoos are commercially not available in the form of ___________________?
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A. Gaseous mixture

B. Powder

C. Emulsion

D. Solution

129. Which of the following test is used for distinguishing among dry oils, semi-drying oils and non drying oils ?
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A. Hunter value test

B. Elaiden test

C. Reichert-Meissl value test

D. Iodine value test

130. Lead is poured into the joint between two _______________ pipes ?
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A. Asbestos cement

B. Mild steel

C. Concrete

D. Cast iron
131. Basicity [%Cao + %MgO + %SiO2) of the slag in Indian blast furnace is in the range of___________________?
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A. 2.0 2.5

B. 1.5 1.8

C. 0.7-1.0

D. 1.1-1.4
132. Rain drops falling through atmospheric air attain limited terminal velocity, because of ____________________?
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A. Viscous force exerted by air

B. Surface tension effects of water

C. Upward thrust due to air

D. Force of gravity

133. Particle nature of cathode rays is proved due to the fact that they ________________?
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A. Produce fluorescence

B. Travel in a straight line

C. Heat the exposed material

D. Get deflected by magnetic electric field
134. Force between the molecules of the same substance is called ______________________ force?
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A. Cohesive

B. Molecular

C. Vander Walls

D. Adhesive

135. Spherical shape of mercury droplets is due to its____________________?
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A. High density

B. High viscosity

C. Low surface tension

D. High surface tension
136. Galvanic corrosion cannot be prevented by___________________?
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A. Anodic protection

B. Usage of largest possible anodic area

C. Cathodic protection

D. Any one of these

137. Addition of small amount of ________________ to grey cast iron is done to produce nodular grey cast iron ?
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A. Magnesium

B. Phosphorous

C. Manganese

D. Chromium

138. For infinite parallel planes having emissivities ?1 & ?2, the interchange factor for radiation from surface 1 to surface 2 is given by__________________?
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A. ?1.?2

B. ?1.?2/(?1 + ?2 ?1.?2)

C. ?1 + ?2

D. (?1 + ?2)/?1.?2

139. In multipass welds, shot peening is done after each pass to__________________?
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A. Introduce texture in the weld

B. Break the continuity of columnar grains

C. Close the surface porosity

D. Flatten the weldment

140. The value of y = cp/cv. at < 500C for air & most common gases can be safely assumed to be_____________________?
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A. 1.4

B. 1

C. 0.8

D. 1.8

141. Window panes of aeroplanes are normally made of_____________________?
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A. Perspex (PMMA)

B. Bakelite (phenol formaldehyde)

C. Polystyrene

D. Teflon (PTFE)

142. Limestone is added in the blast furnace (during pig iron manufacture) to______________________?
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A. Form slag by combining with impurities

B. Supply heat by undergoing exothermic reaction with impurities

C. Reduce the coke consumption

D. Reduce slag viscosity

143. Super heating of steam is done at constant___________________?
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A. Enthalpy

B. Volume

C. Pressure

D. Entropy

144. Silicon crystal can be converted to p-type semi-conductor by doping with__________________?
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A. Boron

B. Nitrogen

C. Carbon

D. Phosphorous

145. Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of Portland cement. The component of Portland cement which first hardens is_____________________?
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A. 5CaO. 3 Al2O3

B. 2CaO. SiO2

C. 3CaO. Al2O3

D. 3CaO. SiO2

146. Oxide layer formed on the non-ferrous metal surface after its annealing is__________________?
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A. Hammered into the surface

B. Removed by acid pickling

C. Left as such to protect the surface

D. Removed with coarse emery cloth

147. The ratio of mass of a neutron to that of an electron is about 1839. What is the ratio of the mass of a proton to that of an electron ?
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A. 1837

B. 10000

C. 159

D. 2537
148. The rolling process cannot be used to produce______________________?
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A. Plates

B. Rods

C. Wires

D. Tubes
149. Laser is a device to produce___________________?
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A. Microwaves

B. A beam of white light

C. A beam of coherent light

D. Gamma rays

150. The capacity of a spring to store energy is called the spring form co-efficient. Stiffness of a spring is measured by the____________________?
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A. Capacity to store energy

B. Load to produce unit deflection

C. Ability to absorb shock

D. Ratio of the wire & coil diameters