MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 8247 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1701. |
As the entropy of the universe is increasing, day by day, the work producing capacity of a heat engine is |
| A. | not changed |
| B. | decreasing |
| C. | increasing |
| D. | data sufficient, can't be predicted |
| Answer» C. increasing | |
| 1702. |
An irreversible process |
| A. | is the analog of linear frictionless motion in machines. |
| B. | is an idealised visualisation of behaviour of a system. |
| C. | yields the maximum amount of work. |
| D. | yields an amount of work less than that of a reversible process. |
| Answer» E. | |
| 1703. |
The expression for the work done for a reversible polytropic process can be used to obtain the expression for work done for all processes, except reversible __________ process. |
| A. | isobaric |
| B. | isothermal |
| C. | adiabatic |
| D. | none of these |
| Answer» C. adiabatic | |
| 1704. |
Joule-Thomson co-efficient depends on the |
| A. | pressure. |
| B. | temperature. |
| C. | both (a) & (b). |
| D. | neither (a) nor (b). |
| Answer» D. neither (a) nor (b). | |
| 1705. |
Undercharging of coal in the by-product coke ovens results in |
| A. | decrease in the c.v. of coke oven gas. |
| B. | increase in its throughput. |
| C. | increase in the c.v. of coke oven gas. |
| D. | no change in the c.v. of coke oven gas. |
| Answer» B. increase in its throughput. | |
| 1706. |
The calorific value of natural gas is about __________ kcal/Nm3. |
| A. | 10, 000 |
| B. | 2500 |
| C. | 25, 000 |
| D. | 35, 000 |
| Answer» B. 2500 | |
| 1707. |
Critical Air Blast (CAB) value of coke is a direct measure of its |
| A. | reactivity |
| B. | hardness |
| C. | strength |
| D. | none of these |
| Answer» B. hardness | |
| 1708. |
The function of secondary combustion air is to |
| A. | pneumatically convey the pulverised coal. |
| B. | completely burn the volatile matter. |
| C. | burn the lumpy coal. |
| D. | none of these. |
| Answer» C. burn the lumpy coal. | |
| 1709. |
The ratio of maximum adiabatic flame temperature in air to that in pure oxygen is always |
| A. | 1 |
| B. | <1 |
| C. | > 1 |
| D. | unpredicatable |
| Answer» C. > 1 | |
| 1710. |
The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is |
| A. | less |
| B. | more |
| C. | same |
| D. | dependent on climatic conditions |
| Answer» B. more | |
| 1711. |
The unit of fugacity is the same as that of the |
| A. | pressure |
| B. | temperature |
| C. | volume |
| D. | molar concentration |
| Answer» B. temperature | |
| 1712. |
Filling of gas from a high pressure cylinder into small bottles is an example of a/an __________ process. |
| A. | equilibrium |
| B. | adiabatic |
| C. | steady |
| D. | unsteady |
| Answer» E. | |
| 1713. |
A large iceberg melts at the base, but not at the top, because of the reason that |
| A. | ice at the base contains impurities which lowers its melting point. |
| B. | due to the high pressure at the base, its melting point reduces. |
| C. | the iceberg remains in a warmer condition at the base. |
| D. | all (a), (b) and (c). |
| Answer» C. the iceberg remains in a warmer condition at the base. | |
| 1714. |
At the critical point of a substance |
| A. | the surface tension vanishes. |
| B. | liquid and vapour have the same density. |
| C. | there is no distinction between liquid and vapour phases. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1715. |
Which of the following is not a reversible process ? |
| A. | Expansion of an ideal gas against constant pressure. |
| B. | Atmospheric pressure vaporisation of water at 100 C. |
| C. | Solution of NaCl in water at 50 C. |
| D. | None of these. |
| Answer» D. None of these. | |
| 1716. |
In an adiabatic process, the |
| A. | heat transfer is zero. |
| B. | temperature change is zero. |
| C. | work done is a path function. |
| D. | enthalpy remains constant. |
| Answer» B. temperature change is zero. | |
| 1717. |
Duringthe phase transition, __________ changes. |
| A. | pressure |
| B. | volume |
| C. | temperature |
| D. | all (a), (b) and (c) |
| Answer» C. temperature | |
| 1718. |
The work done in an adiabatic change in a particular gas depends upon changes in the __________ only. |
| A. | temperature |
| B. | specific heat |
| C. | volume |
| D. | pressure |
| Answer» B. specific heat | |
| 1719. |
The value of gas constant 'R' is |
| A. | 1.987 cal/gm mole K |
| B. | 1.987 BTU/lb. mole R |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» D. neither (a) nor (b) | |
| 1720. |
A nozzle is a device, which |
| A. | increases kinetic energy and decreases pressure. |
| B. | reduces kinetic energy and increases pressure. |
| C. | reduces both kinetic energy and pressure. |
| D. | increases both kinetic energy and pressure. |
| Answer» B. reduces kinetic energy and increases pressure. | |
| 1721. |
The number of degrees of freedom at the triple point of water is |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» B. 1 | |
| 1722. |
Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)? |
| A. | Freon |
| B. | Liquid sulphur dioxide |
| C. | Methyl chloride |
| D. | Ammonia |
| Answer» B. Liquid sulphur dioxide | |
| 1723. |
Internal energy is equal to the heat absorbed in case of a/an __________ process. |
| A. | constant volume |
| B. | polytropic |
| C. | adiabatic |
| D. | constant pressure |
| Answer» B. polytropic | |
| 1724. |
The first law of thermodynamics is a restatement of the law of conservation of |
| A. | mass |
| B. | energy |
| C. | momentum |
| D. | none of these |
| Answer» C. momentum | |
| 1725. |
Equation which relates pressure, volume and temperature of a gas is called the |
| A. | equation of state |
| B. | Gibbs Duhem equation |
| C. | ideal gas equation |
| D. | none of these |
| Answer» B. Gibbs Duhem equation | |
| 1726. |
Joule-Thomson co-efficient for a perfect gas is |
| A. | zero |
| B. | positive |
| C. | negative |
| D. | none of these |
| Answer» B. positive | |
| 1727. |
For a single component two phase mixture, the number of independent variable properties are |
| A. | two |
| B. | one |
| C. | zero |
| D. | three |
| Answer» C. zero | |
| 1728. |
Claussius-Clayperon equation gives accurate result, when the |
| A. | vapour pressure is relatively low and the temperature does not vary over wide limits. |
| B. | vapour obeys the ideal gas law and the latent heat of vaporisation is constant. |
| C. | volume in the liquid state is negligible compared with that in the vapour state. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1729. |
The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called __________ temperature. |
| A. | Boyle |
| B. | inversion |
| C. | critical |
| D. | reduced |
| Answer» B. inversion | |
| 1730. |
The expression for entropy change, S = n Cp . ln (T2/T1), is valid for the __________ of a substance. |
| A. | simultaneous pressure & temperature change |
| B. | heating |
| C. | cooling |
| D. | both (b) and (c) |
| Answer» E. | |
| 1731. |
The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called the __________ temperature. |
| A. | critical |
| B. | Boyle |
| C. | inversion |
| D. | reduced |
| Answer» C. inversion | |
| 1732. |
If the molar heat capacities (Cp or Cv) of the reactants and products of a chemical reaction are identical, then, with the increase in temperature, the heat of reaction will |
| A. | increase |
| B. | decrease |
| C. | remain unaltered |
| D. | increase or decrease ; depends on the particular reaction |
| Answer» D. increase or decrease ; depends on the particular reaction | |
| 1733. |
__________ equation predicts the activity co-efficient from experimental data. |
| A. | Lewis-Randall |
| B. | Margules |
| C. | Van Laar |
| D. | both(b)&(c) |
| Answer» E. | |
| 1734. |
As the temperature is lowered towards the absolute zero, the value of the quantity approaches |
| A. | zero |
| B. | unity |
| C. | infinity |
| D. | none of these |
| Answer» B. unity | |
| 1735. |
An ideal liquid refrigerant should |
| A. | not have a subatmospheric vapour pressure at the temperature in the refrigerator coils. |
| B. | not have unduly high vapour pressure at the condenser temperature. |
| C. | both (a) and (b). |
| D. | have low specific heat. |
| Answer» D. have low specific heat. | |
| 1736. |
If the heat of solution of an ideal gas in a liquid is negative, then its solubility at a given partial pressure varies with the temperature as |
| A. | solubility increases as temperature increases. |
| B. | solubility increases as temperature decreases. |
| C. | solubility is independent of temperature. |
| D. | solubility increases or decreases with temperature depending on the Gibbs free energy change of solution. |
| Answer» C. solubility is independent of temperature. | |
| 1737. |
In case of a reversible process (following pvn = constant), work obtained for trebling the volume (v1 = 1 m3 and v2 3 m3 ) is max imum, when the value of 'n' is |
| A. | 0 |
| B. | 1 |
| C. | <i>y</i> |
| D. | = 1.44 |
| E. | 1.66 |
| Answer» B. 1 | |
| 1738. |
Critical compressibility factor for all substances |
| A. | are more or less constant (vary from 0.2 to 0.3). |
| B. | vary as square of the absolute temperature. |
| C. | vary as square of the absolute pressure. |
| D. | none of these. |
| Answer» B. vary as square of the absolute temperature. | |
| 1739. |
What is the degree of freedom for two mis-cible (non-reacting) substances in vapor-liquid equilibrium forming an azeotrope ? |
| A. | 0 |
| B. | 1 |
| C. | 2 |
| D. | 3 |
| Answer» D. 3 | |
| 1740. |
For a given substance at a specified temperature, activity is __________ to fugacity. |
| A. | directly proportional |
| B. | inversely proportional |
| C. | equal |
| D. | none of these |
| Answer» B. inversely proportional | |
| 1741. |
In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in |
| A. | enhanced COP. |
| B. | decreased COP. |
| C. | no change in the value of COP. |
| D. | increased or decreased COP ; depending upon the type of refrigerant. |
| Answer» B. decreased COP. | |
| 1742. |
For water at 300 C, it has a vapour pressure 8592.7 kPa and fugacity 6738.9 kPa Under these conditions, one mole of water in liquid phase has a volume of 25.28 cm3 and that in vapour phase in 391.1 cm3.Fugacity of water (in kPa) at 9000 kPa will be |
| A. | 6738.9 |
| B. | 6753.5 |
| C. | 7058.3 |
| D. | 9000 |
| Answer» C. 7058.3 | |
| 1743. |
The value of Joule-Thomson co-efficient, in case where cooling occurs after the throttling process is |
| A. | 0 |
| B. | |
| C. | +ve |
| D. | -ve |
| Answer» D. -ve | |
| 1744. |
Adiabatic compression of a saturated water vapour makes it |
| A. | supersaturated |
| B. | superheated |
| C. | both (a) and (b) |
| D. | neither (a) nor (b) |
| Answer» C. both (a) and (b) | |
| 1745. |
The specific heat of saturated water vapour at 100 C is |
| A. | |
| B. | -ve |
| C. | 0 |
| D. | +ve |
| Answer» C. 0 | |
| 1746. |
For a multicomponent system, the term chemical potential is equivalent to the |
| A. | molal concentration difference. |
| B. | molar free energy. |
| C. | partial molar free energy. |
| D. | molar free energy change. |
| Answer» D. molar free energy change. | |
| 1747. |
The change in Gibbs freee energy for vaporisation of a pure substance is |
| A. | positive |
| B. | negative |
| C. | zero |
| D. | may be positive or negative |
| Answer» D. may be positive or negative | |
| 1748. |
In an ideal refrigeration cycle, the change in internal energy of the fluid is |
| A. | +ve |
| B. | -ve |
| C. | 0 |
| D. | either of the above three ; depends on the nature of refrigerant. |
| Answer» D. either of the above three ; depends on the nature of refrigerant. | |
| 1749. |
Free energy |
| A. | decreases in all spontaneous (or irreversible) processes. |
| B. | change during a spontaneous process has a negative value. |
| C. | remains unchanged in reversible processes carried at constant temperature and pressure. |
| D. | all (a), (b) and (c). |
| Answer» E. | |
| 1750. |
"If different processes are used to bring about the same chemical reaction, the enthalpy change is same for all of them". This is __________ law. |
| A. | Hess's |
| B. | Kirchoff's |
| C. | Lavoisier and Laplace |
| D. | none of these |
| Answer» B. Kirchoff's | |