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This section includes 189 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
151. |
The ratio of specific heat at constant pressure () and specific heat at constant volume () is |
A. | equal to one |
B. | less than one |
C. | greater than one |
D. | none of these |
Answer» D. none of these | |
152. |
According to Gay-Lussac law for a perfect gas, / = constant, if is kept constant. |
A. | True |
B. | False |
Answer» B. False | |
153. |
If the value of = 0 in the equation = , then the process is called |
A. | constant volume process |
B. | adiabatic process |
C. | constant pressure process |
D. | isothermal process |
Answer» D. isothermal process | |
154. |
The value of specific heat at constant pressure () is __________ that of at constant volume (). |
A. | less than |
B. | equal to |
C. | more than |
Answer» D. | |
155. |
The value of gas constant () in S. I. units is |
A. | 0.287 J/kgK |
B. | 2.87 J/kgK |
C. | 28.7 J/kgK |
D. | 287 J/kgK |
Answer» E. | |
156. |
The sum of internal energy () and the product of pressure and volume (.) is known as |
A. | workdone |
B. | entropy |
C. | enthalpy |
D. | none of these |
Answer» D. none of these | |
157. |
Water gas is obtained by passing air and a large amount of steam over waste coal at about 650°C. |
A. | Correct |
B. | Incorrect |
Answer» C. | |
158. |
The compression ratio is the ratio of |
A. | swept volume to total volume |
B. | total volume to swept volume |
C. | swept volume to clearance volume |
D. | total volume to clearance volume |
Answer» E. | |
159. |
When the expansion or compression takes place according to the law = , the process is known as |
A. | isothermal process |
B. | adiabatic process |
C. | hyperbolic process |
D. | polytropic process |
Answer» E. | |
160. |
The entropy is a point function and thus it is a property of the same. |
A. | Correct |
B. | Incorrect |
Answer» B. Incorrect | |
161. |
The state of a substance whose evaporation from its liquid state is complete, is known as |
A. | vapour |
B. | perfect gas |
C. | air |
D. | steam |
Answer» C. air | |
162. |
An open cycle gas turbine works on |
A. | Carnot cycle |
B. | Otto cycle |
C. | Joule's cycle |
D. | Stirling cycle |
Answer» D. Stirling cycle | |
163. |
The efficiency of Carnot cycle depends upon |
A. | temperature limits |
B. | pressure ratio |
C. | volume compression ratio |
D. | cut-off ratio and compression ratio |
Answer» B. pressure ratio | |
164. |
The gas turbine cycle with regenerator improves |
A. | thermal efficiency |
B. | work ratio |
C. | avoids pollution |
D. | none of these |
Answer» B. work ratio | |
165. |
When a gas is heated, change takes place in |
A. | pressure |
B. | volume |
C. | temperature |
D. | all of these |
Answer» E. | |
166. |
When a fluid is allowed to expand suddenly into a vaccum chamber through an orifice of large dimensions, the process is known as free expansion process. |
A. | True |
B. | False |
Answer» B. False | |
167. |
According to kinetic theory of gases, the kinetic energy of translation of a molecule is proportional to |
A. | 1/ |
B. | 1/ |
Answer» B. 1/ | |
168. |
The amount of heat given out by the complete combustion of 1 kg of fuel is known as calorific value of solid or liquid fuel. |
A. | True |
B. | False |
Answer» B. False | |
169. |
The conditions of temperature and pressure at 0°C (273K) and 760 mm of Hg pressure are termed as __________ temperature and pressure. |
A. | normal |
B. | standard |
Answer» C. | |
170. |
The value of / for air is |
A. | 1 |
B. | 1.4 |
C. | 1.8 |
D. | 23 |
Answer» C. 1.8 | |
171. |
Which of the following is an intensive property of a thermodynamic system? |
A. | Volume |
B. | Temperature |
C. | Mass |
D. | Energy |
Answer» C. Mass | |
172. |
A triatomic molecule consists of __________ atoms. |
A. | one |
B. | two |
C. | three |
D. | four |
Answer» D. four | |
173. |
A cycle consisting of __________ and two isothermal processes is known as Stirling cycle. |
A. | two constant pressure |
B. | two constant volume |
C. | two isentropic |
D. | one constant pressure, one constant volume |
Answer» C. two isentropic | |
174. |
The ratio of molar specific heats for monoatomic gas is |
A. | 1 |
B. | 1.4 |
C. | 1.67 |
D. | 1.87 |
Answer» D. 1.87 | |
175. |
The general law of expansion or compression is = , The process is said to be hyperbolic, if is equal to |
A. | 0 |
B. | 1 |
C. | γ |
D. | ∝ |
Answer» C. γ | |
176. |
The state of a substance whose evaporation from its liquid state is partial, is known as steam. |
A. | Agree |
B. | Disagree |
Answer» C. | |
177. |
The value of universal gas constant is same for all gases. |
A. | Yes |
B. | No |
Answer» B. No | |
178. |
The numerical value of the thermal capacity and the water equivalent of the substance are the same. |
A. | Agree |
B. | Disagree |
Answer» B. Disagree | |
179. |
The area under the temperature-entropy curve (i. e. - curve) of any thermodynamic process represents the workdone during the process. |
A. | Agree |
B. | Disagree |
Answer» C. | |
180. |
The heating of a gas at constant pressure is governed by Charles' law. |
A. | True |
B. | False |
Answer» B. False | |
181. |
When a gas is heated at constant volume |
A. | its temperature will increase |
B. | its pressure will increase |
C. | both temperature and pressure will increase |
D. | neither temperature nor pressure will increase |
Answer» D. neither temperature nor pressure will increase | |
182. |
The hard coke is obtained when carbonisation of coal is carried out at |
A. | 300° to 500°C |
B. | 500° to700°C |
C. | 700° to 900°C |
D. | 900° to 1100°C |
Answer» E. | |
183. |
According to First law of thermodynamics, |
A. | total internal energy of a system during a process remains constant |
B. | total energy of a system remains constant |
C. | workdone by a system is equal to the heat transferred by the system |
D. | internal energy, enthalpy and entropy during a process remains constant |
Answer» C. workdone by a system is equal to the heat transferred by the system | |
184. |
Stirling cycle consists of |
A. | two constant volume and two isentropic processes |
B. | two constant volume and two isothermal processes |
C. | two constant pressure and two isothermal processes |
D. | one constant volume, one constant pressure and two isentropic processes |
Answer» C. two constant pressure and two isothermal processes | |
185. |
For the same compression ratio, the efficiency of Diesel cycle is __________ Otto cycle. |
A. | greater than |
B. | less than |
C. | equal to |
Answer» C. equal to | |
186. |
In open cycle gas turbine plants |
A. | the indirect heat exchanger and cooler is avoided |
B. | direct combustion system is used |
C. | a condenser is used |
D. | all of the above |
Answer» E. | |
187. |
The efficiency of Ericsson cycle is __________ Carnot cycle. |
A. | greater than |
B. | less than |
C. | equal to |
Answer» D. | |
188. |
One molecule of oxygen consists of __________ atoms of oxygen. |
A. | 2 |
B. | 4 |
C. | 8 |
D. | 16 |
Answer» B. 4 | |
189. |
In an isolated system, neither the heat and work nor the, mass of the working substance crosses the boundary of the system. |
A. | True |
B. | False |
Answer» B. False | |