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MCQOPTIONS
This section includes 430 Mcqs, each offering curated multiple-choice questions to sharpen your Thermodynamics knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
According to Amagat's law |
| A. | the sum of the volume friction is unity |
| B. | there would be no volume change if the components are mixed while holding the temperature and pressure constant |
| C. | all diatomic gases occupy double the volume of monoatomic gases for identical masses |
| D. | None of the above |
| E. | Pulsejet |
| Answer» B. there would be no volume change if the components are mixed while holding the temperature and pressure constant | |
| 152. |
The triple point for carbondioxide is at about -56.7 C and about 5 atm, pressure. It means that |
| A. | Mass transfer at triple point is maximum |
| B. | When CO2 is exposed to a below 5 atmosphere pressure only solid and liquid phase exist together |
| C. | Above 56.7 C CO2 exists only as a liquid |
| D. | Below 57.7 C CO2 exists only in liquid form |
| E. | When solid CO2 is exposed to 1 atm pressure it begins to change directly to gas |
| Answer» F. | |
| 153. |
If the two specific heats of a gas are 0.237 and 0.169 respectively, the volume of 3 kg of air at 27?C under a pressure of 3 ata would be |
| A. | 2.5 cu-m |
| B. | 1 cu-m |
| C. | 0.204 cu-m |
| D. | 1.74 cu-m |
| E. | 1.5 cu-m |
| Answer» D. 1.74 cu-m | |
| 154. |
In which case the heat transferred from the air when compressed from 1.05 ata 15?C to 6.3 ata would be minimum? |
| A. | Adiabatic |
| B. | Polytropic pv1.3 = C |
| C. | Polytropic pv1.31 = C |
| D. | Polytropic pv1.35 = C |
| E. | Isothermal |
| Answer» B. Polytropic pv1.3 = C | |
| 155. |
The velocity potential exists |
| A. | Only for unidirectional flow |
| B. | Only for rotational flow |
| C. | For all types of continuous flow |
| D. | Only for laminar flow |
| E. | Only for irrotational flow |
| Answer» F. | |
| 156. |
Which of the following is not a property of the system |
| A. | Temperature |
| B. | Pressure |
| C. | Specific volume |
| D. | Heat |
| E. | None of the above |
| Answer» E. None of the above | |
| 157. |
Heating wet steam at constant temperature is same as heating at |
| A. | Constant pressure |
| B. | Constant volume |
| C. | Constant enthalpy |
| D. | Constant entropy |
| E. | None of the above |
| Answer» B. Constant volume | |
| 158. |
Internal energy of a perfect gas depends on |
| A. | Temperature, specific heats and entropy |
| B. | Temperature, specific heats and pressure |
| C. | Temperature, specific heats and enthalpy |
| D. | Temperature and specific heats |
| E. | Temperature only |
| Answer» F. | |
| 159. |
The behaviour of which of the following vapour is closer to that of a gas? |
| A. | Wet vapour |
| B. | Wet and superheated vapours |
| C. | Wet and dry vapour |
| D. | Superheated vapour |
| E. | Dry vapour |
| Answer» E. Dry vapour | |
| 160. |
The number of processes in a Rankine cycle is |
| A. | Four |
| B. | Five |
| C. | Three |
| D. | Six |
| E. | Two |
| Answer» B. Five | |
| 161. |
The mixture formation in a carburettor is based on the principle of |
| A. | Venturi principle |
| B. | Pascal's law |
| C. | Law of vapours |
| D. | Daltons law |
| E. | Newtons law of motion |
| Answer» B. Pascal's law | |
| 162. |
Which of the following cycle consists of two isothermal and constant volume processes? |
| A. | Joule cycle |
| B. | Diesel cycle |
| C. | Rankine cycle |
| D. | Otto cycle |
| E. | Ericsson cycle |
| Answer» F. | |
| 163. |
Which of the following remains constant during an adiabatic process? |
| A. | internal energy |
| B. | enthalpy |
| C. | entropy |
| D. | All of the above |
| E. | Pulsejet |
| Answer» D. All of the above | |
| 164. |
By doubling the temperature the radiant heat will increase |
| A. | 16 times |
| B. | microns |
| C. | 4 times |
| D. | 8 times |
| E. | 2 times |
| Answer» B. microns | |
| 165. |
The cycle generally used for gas turbines is |
| A. | Brayton cycle |
| B. | Carnot cycle |
| C. | Dual cycle |
| D. | Otto cycle |
| E. | Rankine cycle |
| Answer» B. Carnot cycle | |
| 166. |
All of the following cycles consists of two isothermal processes EXCEPT |
| A. | Ericsson cycle |
| B. | Stirling cycle |
| C. | Brayton cycle |
| D. | Carnot cycle |
| E. | Pulsejet |
| Answer» D. Carnot cycle | |
| 167. |
The slope of constant pressure line on temperature entropy diagrm is given by |
| A. | 90? |
| B. | T/Cp |
| C. | Cp/T |
| D. | S/T |
| E. | T/S |
| Answer» C. Cp/T | |
| 168. |
Air leaking from a punctured tube is an example of |
| A. | Throttling |
| B. | Constant volume expansion |
| C. | Adiabatic expansion |
| D. | Constant pressure expansion |
| E. | Isothermal expansion |
| Answer» B. Constant volume expansion | |
| 169. |
In all irreversible processes, the entropy of the system |
| A. | Increases |
| B. | Depends on medium |
| C. | Remains constant |
| D. | Sometimes increases and sometimes decreases |
| E. | Reduces to zero |
| Answer» B. Depends on medium | |
| 170. |
During an adiabatic process the change in entropy is |
| A. | Positive or Negative |
| B. | Zero |
| C. | Negative |
| D. | Approximately zero |
| E. | Positive |
| Answer» C. Negative | |
| 171. |
In automobiles clutch is mounted between |
| A. | Gear box and differential |
| B. | Differential and wheels |
| C. | Engine and flywheel |
| D. | Engine and differential |
| E. | Flywheel and gear box |
| Answer» F. | |
| 172. |
Which of the following gas will satisfy, Boyle's law over a wider range of temperatures and pressures? |
| A. | Helium |
| B. | Pulsejet |
| C. | Oxygen |
| D. | Hydrogen |
| E. | Carbon monoxide |
| Answer» B. Pulsejet | |
| 173. |
The ratio of the rise in temperature of a gas when compressed adiabatically to that when compressed isothermally to the same extent is |
| A. | Depends on the gas |
| B. | Pulsejet |
| C. | less than 1 |
| D. | Equal to 1 |
| E. | More than 1 |
| Answer» F. | |
| 174. |
The characteristics of a control volume are |
| A. | There is no material flow across the boundary |
| B. | The volume, shape and position with respect to an observer may change |
| C. | Pulsejet |
| D. | The volume, shape and position with respect to an observer are fixed |
| Answer» E. | |
| 175. |
The efficiency of an ideal (Carnot engine) depends on |
| A. | On the temperature of both the source and the sink |
| B. | On the temperature of the source only |
| C. | On the temperature of the sink only |
| D. | On the construction of engine |
| E. | Working substance |
| Answer» B. On the temperature of the source only | |
| 176. |
The critical temperature of carbondioside is 31.1?C. If the room temperature is 34.7?C, then carbondioxide at room temperature is |
| A. | vapour |
| B. | wet vapour |
| C. | Pulsejet |
| D. | superheated vapour |
| E. | gas |
| Answer» F. | |
| 177. |
The term "pre-whirl" is associated with |
| A. | Gas turbines |
| B. | Super-charged diesel engines |
| C. | Sliding vane type air compressors |
| D. | Reciprocating air compressors |
| E. | Centrifugal air compressors |
| Answer» F. | |
| 178. |
Sadi Carnot was a |
| A. | French engineer |
| B. | Russian engineer |
| C. | Pulsejet |
| D. | British engineer |
| E. | German engineer |
| Answer» B. Russian engineer | |
| 179. |
During isothermal process |
| A. | Pulsejet |
| B. | supply of heat is accompanied by rise in temperature |
| C. | rise in entropy is accompanied by rise in temperature |
| D. | drop in pressure is accompanied by drop in volume |
| E. | rejection of heat is accompanied by decrease in volume |
| Answer» F. | |
| 180. |
Two vessels of volume 5 litres and 3 litres contain air at a pressure of 3 atmospheres and 5 atmospheres respectively. When the two vessels are connected together by a small tube (at constant temperature) the reusltant pressure will be |
| A. | 4.0 atm |
| B. | 5.0 atm |
| C. | 4.5 atm |
| D. | 3.75 atm |
| E. | Pulsejet |
| Answer» E. Pulsejet | |
| 181. |
Cut of ratio in a steam engine is the ratio of |
| A. | Work done by piston after cut off to total work done per cylinder |
| B. | Fraction of piston stroke which the piston has travelled when cut off occurs |
| C. | Pressure at cut off to supply pressure |
| D. | Pressure at cut off to exhaust pressure |
| E. | Pressure at cut off to mean effective pressure |
| Answer» C. Pressure at cut off to supply pressure | |
| 182. |
Two gases X and Y having the same temperature T, the same pressure P and the same volume V are mixed. If the mxiture has the volume V and temperature T, then the pressure of the mixture must be |
| A. | 4P |
| B. | P |
| C. | Pulsejet |
| D. | 2P |
| Answer» E. | |
| 183. |
By applying chike in an automobile we get |
| A. | Stoichiometric mixture |
| B. | Chemically correct mixture |
| C. | Weak mixture |
| D. | Lean mixture |
| E. | Rich mixture |
| Answer» F. | |
| 184. |
A gs which satisfies the Kinetic theory of gases is known as |
| A. | Manoatomic gas |
| B. | Diatomic gas |
| C. | Real gas |
| D. | Perfect gas |
| E. | None of the above |
| Answer» E. None of the above | |
| 185. |
The ratio of enthalpy rise in rotor of a centrifugal compressor to the enthalpy rise in stage is called |
| A. | Adiabatic efficiency |
| B. | Degree of reaction |
| C. | Volumetric efficiency |
| D. | Dynamic pressure ratio |
| E. | Static pressure ratio |
| Answer» C. Volumetric efficiency | |
| 186. |
The heat flows through solids only by |
| A. | Radiation |
| B. | Conduction |
| C. | microns |
| D. | Convection |
| Answer» D. Convection | |
| 187. |
A choke is applied in a car |
| A. | For reduction of speed |
| B. | For increasing speed |
| C. | For starting in hot weather |
| D. | For fuel economy |
| E. | For starting in cold weather |
| Answer» F. | |
| 188. |
The solubility of a gas in a liquid at small concentration is represented by |
| A. | Joules equation |
| B. | Van der Waal's equation |
| C. | Henry's law |
| D. | Claperyon equation |
| E. | Roults law |
| Answer» D. Claperyon equation | |
| 189. |
An amount of heat given to a gas under isothermal conditions will be |
| A. | For a temperature rise |
| B. | For doing external work |
| C. | For doing external work and also for a temperature rise |
| D. | For increasing the internal energy of the gas |
| E. | None of the above |
| Answer» C. For doing external work and also for a temperature rise | |
| 190. |
Draught ensures supply of |
| A. | Air for combustion |
| B. | Feed water |
| C. | Coad to the boiler |
| D. | Superheated steam |
| E. | Isothermal |
| Answer» B. Feed water | |
| 191. |
A system |
| A. | Is a specified region, not necessarily of constant volume, where transfer of energy and/or mass are to be studied |
| B. | Is a region of constant mass and only energy is allowed to cross the boundaries |
| C. | Cannot transfer either energy or mass to or from the surroundings |
| D. | Has a mass transfer across its boundaries and the mass within the system is not constant |
| E. | None of the above |
| Answer» B. Is a region of constant mass and only energy is allowed to cross the boundaries | |
| 192. |
which of the following set of quantities contains intensive variables? |
| A. | Kinetic energy, potential energy and internal energy |
| B. | Pulsejet |
| C. | Work, energy and weight |
| D. | Mass, volume and area |
| E. | Pressure, temperature and density |
| Answer» F. | |
| 193. |
In case of ideal triatomic gas, the ratio of specific heats Cp/Cv would be |
| A. | 1 |
| B. | 1.33 |
| C. | 1.4 |
| D. | 1.41 |
| E. | 1.67 |
| Answer» C. 1.4 | |
| 194. |
In case of centrifugal compressors the phenomenon of unsteady, periodic and reversed flow is known as |
| A. | Surging |
| B. | Stalling |
| C. | Choking |
| D. | Either of above |
| E. | None of the above |
| Answer» B. Stalling | |
| 195. |
The difference between two specific heats of a gas is equal to universal gas constant |
| A. | When 1 gm molecule heated |
| B. | When 1 molecule of gas is heated |
| C. | When 1 gm molecule heated |
| D. | When 1 gm of gas is heated |
| E. | When any amount of gas is heated |
| Answer» D. When 1 gm of gas is heated | |
| 196. |
1 cu-m of steam having dryness franction 0.85 at 12 ata mixes with 1.5 kg of water at 12?C at constant pressure. The dryness fraction of resulting steam would be |
| A. | 0.6 |
| B. | 0.5 |
| C. | 0.85 |
| D. | 0.637 |
| E. | 0.75 |
| Answer» E. 0.75 | |
| 197. |
The fastest moving gas molecules are those of |
| A. | Pulsejet |
| B. | Oxygen |
| C. | Hydrogen |
| D. | Nitrogen |
| E. | Chlorine |
| Answer» D. Nitrogen | |
| 198. |
The difference between two specific heats of a gas is equal to universal constant when |
| A. | 1 mole of gas is heated |
| B. | 1 gm molecule of gas is heated |
| C. | 1 gm of gas is heated |
| D. | Pulsejet |
| E. | any amount of gas is heated |
| Answer» C. 1 gm of gas is heated | |
| 199. |
"The internal energy of a gas is a function of temperature". Which of the following name is associated with the above law? |
| A. | Regnault |
| B. | Dalton |
| C. | Boyle |
| D. | Charle |
| E. | Joule |
| Answer» F. | |
| 200. |
In centrifugal compressors, the ratio of outlet whirl velocity to blade velocity at outlet is known as |
| A. | Feedback factor |
| B. | Slip factor |
| C. | Reheat factor |
| D. | Gauge factor |
| E. | Velocity factor |
| Answer» C. Reheat factor | |