MCQOPTIONS
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MCQOPTIONS
This section includes 425 Mcqs, each offering curated multiple-choice questions to sharpen your Graduate Aptitude Test (GATE) knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
The greater the pressure difference in throttling, the lesser is the irreversibility. |
| A. | Yes |
| B. | No |
| C. | Can't say |
| D. | None of these |
| Answer» C. Can't say | |
| 152. |
A machine which violates the first law of thermodynamics is known as perpetual motion machine of the second kind. |
| A. | Correct |
| B. | Incorrect |
| C. | Can't say |
| D. | None of these |
| Answer» C. Can't say | |
| 153. |
According to Kelvin-Planck's statement of second law of thermodynamics, |
| A. | it is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work |
| B. | it is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work |
| C. | it is impossible to construct a device which operates in a cyclic process and produces no effect other than the transfer of heat from a cold body to a hot body |
| D. | none of the above |
| Answer» B. it is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work | |
| 154. |
The efficiency of the Carnot cycle is (where T1 and T2 = Highest and lowest temperature during the cycle) |
| A. | (T1/T2) - 1 |
| B. | 1 - (T1/T2) |
| C. | 1 - (T2/T1) |
| D. | 1 + (T2/T1) |
| Answer» D. 1 + (T2/T1) | |
| 155. |
The amount of heat obtained by the complete combustion of 1 kg of a fuel when the products of its combustion are cooled down to the temperature of supplied air is called __________ calorific value offuel. |
| A. | higher |
| B. | lower |
| C. | Can't say |
| D. | None of these |
| Answer» B. lower | |
| 156. |
One molecule of oxygen is __________ times heavier than the hydrogen atom. |
| A. | 12 |
| B. | 14 |
| C. | 16 |
| D. | 32 |
| Answer» E. | |
| 157. |
The calorific value of gaseous fuel is expressed in |
| A. | kJ |
| B. | kJ/kg |
| C. | kJ/m² |
| D. | kJ/m³ |
| Answer» E. | |
| 158. |
The kinetic energy per kg molecule of any gas at absolute temperature T is equal to (where Ru = Universal gas constant) |
| A. | Ru x T |
| B. | 1.5 Ru x T |
| C. | 2 Ru x T |
| D. | 3 Ru x T |
| Answer» C. 2 Ru x T | |
| 159. |
The property of the system, whose value for the entire system is equal to the sum of their values for the individual parts of the system is called extensive property |
| A. | Yes |
| B. | No |
| C. | Can't say |
| D. | None of these |
| Answer» B. No | |
| 160. |
Which of the following is a reversible non-flow process? |
| A. | Isochoric process |
| B. | Isobaric process |
| C. | Hyperbolic process |
| D. | all of these |
| Answer» E. | |
| 161. |
One kg of carbon produces __________ kg of carbon dioxide. |
| A. | 3/7 |
| B. | 7/3 |
| C. | 11/3 |
| D. | 3/11 |
| Answer» D. 3/11 | |
| 162. |
The change of entropy, when heat is absorbed by the gas, is |
| A. | positive |
| B. | negative |
| C. | positive or negative |
| D. | None of these |
| Answer» B. negative | |
| 163. |
Which of the following is an intensive property of a thermodynamic system? |
| A. | Volume |
| B. | Temperature |
| C. | Mass |
| D. | Energy |
| Answer» C. Mass | |
| 164. |
The reading of the pressure gauge fitted on a vessel is 25 bar. The atmospheric pressure is 1.03 bar and the value of 'g' is 9.81 m/s². The absolute pressure in the vessel is |
| A. | 23.97 bar |
| B. | 25 bar |
| C. | 26.03 bar |
| D. | 34.81 bar |
| Answer» D. 34.81 bar | |
| 165. |
The ratio of root mean square velocity to average velocity of gas molecules at a particular temperature is |
| A. | 0.086 |
| B. | 1.086 |
| C. | 3.086 |
| D. | 4.086 |
| Answer» C. 3.086 | |
| 166. |
Steam coal is a |
| A. | pulverised coal |
| B. | brown coal |
| C. | coking bituminous coal |
| D. | non-coking bituminous coal |
| Answer» E. | |
| 167. |
The entropy of the universe is continually on the increase. |
| A. | Correct |
| B. | Incorrect |
| C. | Can't say |
| D. | None of these |
| Answer» B. Incorrect | |
| 168. |
In an extensive property of a thermodynamic system |
| A. | extensive heat is transferred |
| B. | extensive work is done |
| C. | extensive energy is utilised |
| D. | none of these |
| Answer» E. | |
| 169. |
High air-fuel ratio in gas turbines |
| A. | increases power output |
| B. | improves thermal efficiency |
| C. | reduces exhaust temperature |
| D. | do not damage turbine blades |
| Answer» D. do not damage turbine blades | |
| 170. |
Kelvin-Planck's law deals with |
| A. | conservation of work |
| B. | conservation of heat |
| C. | conversion of heat into work |
| D. | conversion of work into heat |
| Answer» D. conversion of work into heat | |
| 171. |
The fuel mostly used in blast furnace for extracting pig iron from iron ores is |
| A. | hard coke |
| B. | soft coke |
| C. | pulverised coal |
| D. | bituminous coal |
| Answer» B. soft coke | |
| 172. |
One kg of carbon monoxide requires 4/7 kg of oxygen and produces |
| A. | 11/3 kg of carbon dioxide gas |
| B. | 7/3 kg of carbon monoxide gas |
| C. | 11/7 kg of carbon dioxide gas |
| D. | 8/3 kg of carbon monoxide gas |
| Answer» D. 8/3 kg of carbon monoxide gas | |
| 173. |
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 |
| C. | Can't say |
| D. | None of these |
| Answer» B. False | |
| 174. |
Producer gas is obtained by |
| A. | partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast |
| B. | carbonisation of bituminous coal |
| C. | passing steam over incandescent coke |
| D. | passing air and a large amount of steam over waste coal at about 650°C |
| Answer» B. carbonisation of bituminous coal | |
| 175. |
A closed system is one in which heat and work crosses the boundary of the system but the mass of the working substance does not crosses the boundary of the system. |
| A. | Yes |
| B. | No |
| C. | Can't say |
| D. | None of these |
| Answer» B. No | |
| 176. |
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 |
| C. | Can't say |
| D. | None of these |
| Answer» C. Can't say | |
| 177. |
The thermal efficiency of an ideal gas turbine plant is given by (where r = Pressure ratio) |
| A. | rγ - 1 |
| B. | 1 - rγ - 1 |
| C. | 1 - (1/r) γ/γ - 1 |
| D. | 1 - (1/r) γ - 1/ γ |
| Answer» E. | |
| 178. |
It is __________ to make an engine working on a Carnot cycle. |
| A. | possible |
| B. | impossible |
| C. | Can't say |
| D. | None of these |
| Answer» C. Can't say | |
| 179. |
The smallest quantity of a substance, which can exist by itself in a chemically recognizable form is known as |
| A. | element |
| B. | compound |
| C. | atom |
| D. | molecule |
| Answer» E. | |
| 180. |
Carnot cycle has maximum efficiency for |
| A. | petrol engine |
| B. | diesel engine |
| C. | reversible engine |
| D. | irreversible engine |
| Answer» D. irreversible engine | |
| 181. |
The general law for the expansion or compression of gases, is |
| A. | pv = C |
| B. | pv = m R T |
| C. | pvn = C |
| D. | pvγ = C |
| Answer» D. pvγ = C | |
| 182. |
The ultimate analysis of coal consists of the determination of the percentage of |
| A. | carbon |
| B. | hydrogen and nitrogen |
| C. | sulphur and ash |
| D. | all of these |
| Answer» E. | |
| 183. |
The heating of gas at constant volume is governed by |
| A. | Boyle's law |
| B. | Charles' law |
| C. | Gay-Lussac law |
| D. | Avogadro's law |
| Answer» D. Avogadro's law | |
| 184. |
Otto cycle consists of |
| A. | two constant volume and two isentropic processes |
| B. | two constant pressure and two isentropic processes |
| C. | two constant volume and two isothermal processes |
| D. | one constant pressure, one constant volume and two isentropic processes |
| Answer» B. two constant pressure and two isentropic processes | |
| 185. |
The air standard efficiency of an Otto cycle is given by (where r = Compression ratio, and γ = Ratio of specific heats) |
| A. | 1 - rγ - 1 |
| B. | 1 + rγ - 1 |
| C. | 1 - (1/ rγ - 1) |
| D. | 1 + (1/ rγ - 1) |
| Answer» D. 1 + (1/ rγ - 1) | |
| 186. |
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 | |
| 187. |
Relation between cp and cv is given by (where cp = Specific heat at constant pressure, cv = Specific heat at constant volume, γ = cp/cv, known as adiabatic index, and R = Gas constant) |
| A. | cv/ cp =R |
| B. | cp - cv = R |
| C. | cv = R/ γ-1 |
| D. | Both b and c |
| Answer» E. | |
| 188. |
The natural petroleum may be separated into |
| A. | petrol |
| B. | kerosene |
| C. | fuel oil |
| D. | lubricating oil |
| Answer» E. | |
| 189. |
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 | |
| 190. |
A definite area or a space where some thermodynamic process takes place is known as |
| A. | thermodynamic system |
| B. | thermodynamic cycle |
| C. | thermodynamic process |
| D. | thermodynamic law |
| Answer» B. thermodynamic cycle | |
| 191. |
Reversed Joule cycle is known as |
| A. | Carnot cycle |
| B. | Bell-Coleman cycle |
| C. | Rankine cycle |
| D. | Stirling cycle |
| Answer» C. Rankine cycle | |
| 192. |
The numerical value of the thermal capacity and the water equivalent of the substance are the same. |
| A. | Agree |
| B. | Disagree |
| C. | Can't say |
| D. | None of these |
| Answer» B. Disagree | |
| 193. |
The standard value of atmospheric pressure taken at sea level is |
| A. | 1.013 bar |
| B. | 760 mm of Hg |
| C. | 1013 x 102 N/m² |
| D. | all of these |
| Answer» E. | |
| 194. |
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 |
| C. | Can't say |
| D. | None of these |
| Answer» B. False | |
| 195. |
The specific volume of a system is an __________ property. |
| A. | extensive |
| B. | intensive |
| C. | Can't say |
| D. | None of these |
| Answer» C. Can't say | |
| 196. |
When the gas is heated at constant volume, the heat supplied |
| A. | increases the internal energy of the gas and increases the temperature of the gas |
| B. | does some external work during expansion |
| C. | Both a and b |
| D. | None of these |
| Answer» B. does some external work during expansion | |
| 197. |
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 | |
| 198. |
The isothermal and isentropic processes are reversible non-flow processes. |
| A. | Agree |
| B. | Disagree |
| C. | Can't say |
| D. | None of these |
| Answer» B. Disagree | |
| 199. |
One kg of ethylene (C₂H₄) requires 2 kg of oxygen and produces 22/7 kg of carbon dioxide and __________ kg of water or steam. |
| A. | 9/7 |
| B. | 11/7 |
| C. | 7/4 |
| D. | 11/4 |
| Answer» B. 11/7 | |
| 200. |
When wood is heated with a limited supply of air to a temperature not less than 280°C, the resulting fuel is |
| A. | coke |
| B. | wood charcoal |
| C. | bituminous coal |
| D. | briquetted coal |
| Answer» C. bituminous coal | |