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This section includes 463 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
101. |
Compounding                      efficiency at low speed. |
A. | decrease |
B. | increase |
C. | maximizes |
D. | none of the mentioned |
Answer» C. maximizes | |
102. |
Reaction turbine works with the force obtained from change in pressure energy. |
A. | true |
B. | false |
Answer» B. false | |
103. |
A turbine having alternate blades and nozzles is called as |
A. | impulse turbine |
B. | reaction turbine |
C. | impulse & reaction turbine |
D. | none of the mentioned |
Answer» B. reaction turbine | |
104. |
In condensing turbines vacuum is obtained by |
A. | sudden pressure drop |
B. | removal of non condensable gases |
C. | sudden drop in pressure and by removal of non condensable gases |
D. | none of the mentioned |
Answer» D. none of the mentioned | |
105. |
In velocity compounding the steam is expanded from the boiler pressure to condenser pressure in one set of stationary blades on nozzle. |
A. | true |
B. | false |
Answer» B. false | |
106. |
Which statement about impulse turbine is true? |
A. | steam expands over blades |
B. | steam expends completely in stationary nozzels |
C. | steam expends partially over nozzle and turbine blades |
D. | steam expends over blades incompletely |
Answer» C. steam expends partially over nozzle and turbine blades | |
107. |
Which fuel has the lightest liquid petroleum fraction? |
A. | diesel |
B. | petrol |
C. | distillate |
D. | kerosene |
Answer» C. distillate | |
108. |
What does regenerative air preheater consists of? |
A. | rotor |
B. | skewers |
C. | propeller |
D. | piston |
Answer» B. skewers | |
109. |
Tubular air preheater of a boiler is also called as |
A. | recuperative air preheater |
B. | elliptical air preheater |
C. | ovoid air preheater |
D. | squarish air preheater |
Answer» B. elliptical air preheater | |
110. |
Gas flows through the nozzle from an area of            pressure (called the chamber) to one of            pressure |
A. | high, low |
B. | low, high |
C. | same, same |
D. | constant, infinite |
Answer» B. low, high | |
111. |
When a gas is pushed through a pipe, the gaseous molecules are                    by the pipe’s walls |
A. | attracted |
B. | absorbed |
C. | deflected |
D. | dissipated |
Answer» D. dissipated | |
112. |
A cubical block rests on an inclined plane of μ = 1/√3, determine the angle of inclination when the block just slides down the inclined plane? |
A. | 40° |
B. | 50° |
C. | 30° |
D. | 20° |
Answer» D. 20° | |
113. |
The coefficient of kinetic friction is less than the coefficient of static friction. |
A. | true |
B. | false |
Answer» B. false | |
114. |
Compressible flow is a flow that deals with |
A. | fluid temperature |
B. | fluid pressure |
C. | fluid density |
D. | fluid geometry |
Answer» D. fluid geometry | |
115. |
The exit velocity in the nozzle increases as per |
A. | stagnation point |
B. | continuity equation |
C. | prandtl number |
D. | newton’s law |
Answer» C. prandtl number | |
116. |
Critical pressure ratio is ratios of pressures at                    discharge. |
A. | minimum |
B. | none of the mentioned |
C. | optimum |
D. | maximum |
Answer» E. | |
117. |
A nozzle used to send fluid in coherent stream is called as |
A. | jet |
B. | high velocity nozzle |
C. | every nozzle sends fluid in coherent stream |
D. | none of the mentioned |
Answer» B. high velocity nozzle | |
118. |
In fountains the type of nozzle used is |
A. | none of the mentioned |
B. | turbulent jet |
C. | high speed nozzle |
D. | laminar jet |
Answer» E. | |
119. |
Cooling towers are rated in terms of |
A. | approach |
B. | range |
C. | both of the mentioned |
D. | none of the |
Answer» D. none of the | |
120. |
When humidity ratio of air ____ air is said to be dehumidified. |
A. | increases |
B. | decreases |
C. | remains constant |
D. | none of the mentioned |
Answer» C. remains constant | |
121. |
When unsaturated air flows over a sheet of water in an insulated chamber |
A. | specific humidity of air decreases |
B. | the water evaporates |
C. | both air and water are cooled during evaporation |
D. | all of the mentioned |
Answer» B. the water evaporates | |
122. |
The wet bulb temperature is the ____ temperature recorded by moistened bulb. |
A. | lowest |
B. | highest |
C. | atmospheric |
D. | none of the mentioned |
Answer» B. highest | |
123. |
The COP of absorption refrigeration system is |
A. | low |
B. | high |
C. | equal to that of vapour compression refrigeration system |
D. | none of the mentioned |
Answer» B. high | |
124. |
Water is used as a ____ in air conditioning units. |
A. | absorbent |
B. | refrigerant |
C. | absorbent and refrigerant |
D. | none of the mentioned |
Answer» C. absorbent and refrigerant | |
125. |
why is an analyser-rectifier combination is used in absorption refrigeration cycle? |
A. | to increase the amount of water vapour in ammonia vapour |
B. | to decrease the amount of water vapour in ammonia vapour |
C. | to eliminate the water vapour from ammonia vapour |
D. | all of the mentioned |
Answer» D. all of the mentioned | |
126. |
The vapour going to condenser is ____ in temperature and ____ in ammonia. |
A. | higher, less |
B. | higher, richer |
C. | lower, less |
D. | lower, richer |
Answer» E. | |
127. |
An increase in diameter means a _________ heat transfer coefficient. |
A. | larger |
B. | smaller |
C. | zero |
D. | infinite |
Answer» C. zero | |
128. |
If there is a decrease in viscosity, the heat transfer coefficient ____________ |
A. | increase |
B. | decrease |
C. | remains same |
D. | becomes zero |
Answer» B. decrease | |
129. |
Double pipe water cooling condensers have a capacity at around ________ |
A. | 10 tr |
B. | 20 tr |
C. | 30 tr |
D. | 50 tr |
Answer» B. 20 tr | |
130. |
In evaporative condensers, ___________ used to extract heat from the condensing refrigerant. |
A. | air is |
B. | both air and water are |
C. | water is |
D. | either air or water is |
Answer» C. water is | |
131. |
Shell and coil type condensers have a capacity at around ________ |
A. | 10 tr |
B. | 20 tr |
C. | 30 tr |
D. | 50 tr |
Answer» E. | |
132. |
Which type of fins are the most commonly used fin type in condensers? |
A. | annular fin |
B. | plate type fins |
C. | tube fin |
D. | extended double pipe |
Answer» C. tube fin | |
133. |
What is the relation between heat rejection ratio (HRR) and Coefficient of performance (COP)? |
A. | hrr = 1 + 1/cop |
B. | hrr = 1+ cop |
C. | hrr = cop/2 |
D. | hrr = 1/cop |
Answer» B. hrr = 1+ cop | |
134. |
Evaporative condensers are used in places where water is _________ |
A. | scarce |
B. | plenty |
C. | moderately available |
D. | sufficient |
Answer» B. plenty | |
135. |
Evaporative condensers combine the features of a _____________ in a single unit. |
A. | cooling tower and water-cooled condenser |
B. | falling tower and water-cooled condenser |
C. | cooling tower and air condenser |
D. | rising film tower and water-cooled condenser |
Answer» B. falling tower and water-cooled condenser | |
136. |
In traditional Air conditioners in home appliances, what is the type of condenser used? |
A. | natural convection type |
B. | forced convection type |
C. | flash type |
D. | rotary condensers |
Answer» C. flash type | |
137. |
What is the meaning of heat rejection ratio (HRR) of a condenser? |
A. | ratio of heat rejected to the heat absorbed |
B. | ratio of heat absorbed to the heat rejected |
C. | ratio of heat required to the heat lost |
D. | ratio of heat wasted in a cycle to the heat absorbed |
Answer» B. ratio of heat absorbed to the heat rejected | |
138. |
In traditional Refrigerators in home appliances, what is the type of condenser used? |
A. | natural convection type |
B. | forced convection type |
C. | furnace type |
D. | rotary condensers |
Answer» B. forced convection type | |
139. |
Condensers and evaporators together form a ____________ |
A. | heat exchanger |
B. | refrigeration system |
C. | thermocouple |
D. | heating system |
Answer» C. thermocouple | |
140. |
The process of extraction of the certain required amount of water from air is known as ___________ |
A. | heating |
B. | cooling |
C. | humidification |
D. | dehumidification |
Answer» E. | |
141. |
The reciprocal of thermal conductivity is known as __________ |
A. | thermal conductance |
B. | surface resistance |
C. | specific conductance |
D. | thermal resistivity |
Answer» E. | |
142. |
The total loss in a tertiary cycle is? |
A. | sum of losses in the individual cycles |
B. | product of losses in the individual cycles |
C. | sum of products of individual losses |
D. | none of the mentioned |
Answer» C. sum of products of individual losses | |
143. |
In case of mercury-steam-sulphur dioxide cycle, which is the bottoming fluid? |
A. | mercury |
B. | steam |
C. | sulphur dioxide |
D. | cannot say |
Answer» D. cannot say | |
144. |
Room air conditioners and packaged units are examples of _________ |
A. | direct expansion systems |
B. | indirect expansion systems |
C. | chilled water systems |
D. | indirect contraction systems |
Answer» B. indirect expansion systems | |
145. |
In case of Sodium-mercury-steam cycle, which is the topping fluid? |
A. | mercury |
B. | steam |
C. | sodium |
D. | cannot say |
Answer» D. cannot say | |
146. |
Which of these can be used as a fluid in the bottoming fluid? |
A. | mercury |
B. | ammonia |
C. | calcium |
D. | sodium |
Answer» C. calcium | |
147. |
Which of these can also be used as a topping fluid? |
A. | sodium |
B. | calcium |
C. | boron |
D. | titanium |
Answer» B. calcium | |
148. |
The addition of sulphur dioxide in a tertiary cycle is at? |
A. | high temperature |
B. | low temperature |
C. | too high temperature |
D. | none of the mentioned |
Answer» C. too high temperature | |
149. |
In the mercury steam cycle, the steam cycle is called? |
A. | bottoming cycle |
B. | middle cycle |
C. | topping cycle |
D. | none of the mentioned |
Answer» B. middle cycle | |
150. |
Apart from mercury & steam, which of these is a component of tertiary cycle? |
A. | nitrogen di-oxide |
B. | water |
C. | carbon di-oxide |
D. | sulphur di-oxide |
Answer» E. | |