MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 1092 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 801. |
_ The value of specific heat at constant pressure (cp) is __________ that of at constant volume (cv).$? |
| A. | Less than |
| B. | Equal to |
| C. | More than |
| D. | None of these |
| Answer» D. None of these | |
| 802. |
_ When the gas is heated at constant volume, the heat supplied$? |
| 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 | |
| 803. |
_ Steam coal is a$? |
| A. | Pulverized coal |
| B. | Brown coal |
| C. | Coking bituminous coal |
| D. | Non-coking bituminous coal |
| Answer» E. | |
| 804. |
_ The value of cp/cv for air is$? |
| A. | 1 |
| B. | 1.4 |
| C. | 1.45 |
| D. | 2.3 |
| Answer» C. 1.45 | |
| 805. |
_ The specific heat of water is$? |
| A. | 2.512 |
| B. | 1.817 |
| C. | 4.187 |
| D. | None of these |
| Answer» D. None of these | |
| 806. |
_ A molecule consisting of one atom is known as$? |
| A. | Mono-atomic |
| B. | Di-atomic |
| C. | Tri-atomic |
| D. | Poly-atomic |
| Answer» B. Di-atomic | |
| 807. |
_ The entropy of water at 0°C is assumed to be$? |
| A. | 0 |
| B. | -1 |
| C. | 1 |
| D. | 2 |
| Answer» B. -1 | |
| 808. |
_ The absolute zero pressure will be$? |
| A. | When molecular momentum of the system becomes zero |
| B. | At sea level |
| C. | At the temperature of - 273 K |
| D. | At the center of the earth |
| Answer» B. At sea level | |
| 809. |
_ The unit of pressure in S.I. units is$? |
| A. | kg/cm² |
| B. | mm of water column |
| C. | Pascal |
| D. | Dyne per square cm |
| Answer» D. Dyne per square cm | |
| 810. |
_ The unit of power in S.I. units is$? |
| A. | Newton |
| B. | Pascal |
| C. | Erg |
| D. | Watt |
| Answer» E. | |
| 811. |
_ The mass of flue gas per kg of fuel is the ratio of the$? |
| A. | Mass of oxygen in 1 kg of flue gas to the mass of oxygen in 1 kg of fuel |
| B. | Mass of oxygen in 1 kg of fuel to the mass of oxygen in 1 kg of flue gas |
| C. | Mass of carbon in 1 kg of flue gas to the mass of carbon in 1 kg of fuel |
| D. | Mass of carbon in 1 kg of fuel to the mass of carbon in 1 kg of flue gas |
| Answer» D. Mass of carbon in 1 kg of fuel to the mass of carbon in 1 kg of flue gas | |
| 812. |
_ The efficiency of Diesel cycle depends upon$? |
| A. | Pressure ratio |
| B. | Cut-off ratio and compression ratio |
| C. | Temperature limits |
| D. | Compression ratio |
| Answer» C. Temperature limits | |
| 813. |
_ Which of the following cycles has maximum efficiency?$? |
| A. | Rankine |
| B. | Stirling |
| C. | Carnot |
| D. | Brayton |
| Answer» D. Brayton | |
| 814. |
_ A perfect gas at 27°C is heated at constant pressure till its volume is double. The final temperature is$? |
| A. | 54°C |
| B. | 327°C |
| C. | 108°C |
| D. | 654°C |
| Answer» C. 108¬¨‚àûC | |
| 815. |
_ The atomic mass of nitrogen is __________ oxygen.$? |
| A. | Equal to |
| B. | Less than |
| C. | More than |
| D. | None of these |
| Answer» C. More than | |
| 816. |
_ Characteristic gas constant of a gas is equal to$? |
| A. | Cp /Cv |
| B. | Cv /Cp |
| C. | Cp - Cv |
| D. | Cp + Cv |
| Answer» D. Cp + Cv | |
| 817. |
_ The sum of internal energy (U) and the product of pressure and volume (p.v) is known as$? |
| A. | Work done |
| B. | Entropy |
| C. | Power |
| D. | Enthalpy |
| Answer» E. | |
| 818. |
_ The efficiency of the dual combustion cycle for the same compression ratio is __________ Diesel cycle.$? |
| A. | Greater than |
| B. | Less than |
| C. | Equal to |
| D. | None of these |
| Answer» B. Less than | |
| 819. |
_ A process, in which the temperature of the working substance remains constant during its expansion or compression, is called$? |
| A. | Adiabatic process |
| B. | Isothermal process |
| C. | Hyperbolic process |
| D. | Polytropic process |
| Answer» C. Hyperbolic process | |
| 820. |
_ For the same compression ratio, the efficiency of dual combustion cycle is$? |
| A. | Greater than Diesel cycle and less than Otto cycle |
| B. | Greater than Diesel cycle |
| C. | Less than Diesel cycle |
| D. | Less than Diesel cycle and greater than Otto cycle |
| Answer» B. Greater than Diesel cycle | |
| 821. |
_ 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)$? |
| A. | cv/ cp =R |
| B. | cp - cv = R |
| C. | cv = R/ γ-1 |
| D. | Both (B) and (C) |
| Answer» E. | |
| 822. |
_ The amount of heat required to raise the temperature of the unit mass of gas through one degree at constant volume, is called$? |
| A. | Kilo Joule |
| B. | Specific heat at constant volume |
| C. | Specific heat at constant pressure |
| D. | None of these |
| Answer» C. Specific heat at constant pressure | |
| 823. |
_ The ratio of root mean square velocity to average velocity of gas molecules at a particular temperature is$? |
| A. | 0.086 |
| B. | 1.086 |
| C. | 1.086 |
| D. | 4.086 |
| Answer» C. 1.086 | |
| 824. |
_ The general gas energy equation is (where Q1 - 2 = Heat supplied, dU = Change in internal energy, and W1 - 2 = Work done in heat units)$? |
| A. | Q1 - 2 = dU + W1 - 2 |
| B. | Q1 - 2 = dU - W1 - 2 |
| C. | Q1 - 2 = dU/W1 - 2 |
| D. | Q1 - 2 = dU √ó W1 - 2 |
| Answer» B. Q1 - 2 = dU - W1 - 2 | |
| 825. |
_ The standard value of atmospheric pressure taken at sea level is$? |
| A. | 1.013 bar |
| B. | 760 mm of Hg |
| C. | 1013 √ó 102 N/m2 |
| D. | All of these |
| Answer» E. | |
| 826. |
_ According to Avogadro's law, for a given pressure and temperature, each molecule of a gas$? |
| A. | Occupies same volume |
| B. | Occupies volume proportional to its specific weight |
| C. | Occupies volume inversely proportional to its molecular weight |
| D. | Occupies volume inversely proportional to its specific weight |
| Answer» B. Occupies volume proportional to its specific weight | |
| 827. |
_ Which of the following is the correct statement?$? |
| A. | All the reversible engines have the same efficiency. |
| B. | All the reversible and irreversible engines have the same efficiency. |
| C. | Irreversible engines have maximum efficiency. |
| D. | All engines are designed as reversible in order to obtain maximum efficiency. |
| Answer» D. All engines are designed as reversible in order to obtain maximum efficiency. | |
| 828. |
_ The statement that molecular weights of all gases occupy the same volume is known as$? |
| A. | Avogadro's hypothesis |
| B. | Dalton's law |
| C. | Gas law |
| D. | Law of thermodynamics |
| Answer» B. Dalton's law | |
| 829. |
_ If the value of n = 0 in the equation pvn = C, then the process is called$? |
| A. | Constant volume process |
| B. | Adiabatic process |
| C. | Constant pressure process |
| D. | Isothermal process |
| Answer» D. Isothermal process | |
| 830. |
_ A definite area or a space where some thermodynamic process takes place is known as$? |
| A. | Thermodynamic system |
| B. | Thermodynamic cycle |
| C. | Thermodynamic process |
| D. | Thermodynamic law |
| Answer» B. Thermodynamic cycle | |
| 831. |
_ Which of the following is correct?$? |
| A. | Absolute pressure = Gauge pressure + Atmospheric pressure |
| B. | Gauge pressure = Absolute pressure + Atmospheric pressure |
| C. | Atmospheric pressure = Absolute pressure + Gauge pressure |
| D. | Absolute pressure = Gauge pressure - Atmospheric pressure |
| Answer» B. Gauge pressure = Absolute pressure + Atmospheric pressure | |
| 832. |
_ Which of the following variables controls the physical properties of a perfect gas?$? |
| A. | Pressure |
| B. | Temperature |
| C. | Volume |
| D. | All of the above |
| Answer» E. | |
| 833. |
_ The gas constant (R) is equal to the __________ of two specific heats.$? |
| A. | Product |
| B. | Sum |
| C. | Difference |
| D. | Ratio |
| Answer» D. Ratio | |
| 834. |
_ The thermodynamic difference between a Rankine cycle working with saturated steam and the Carnot cycle is that$? |
| A. | Carnot cycle can't work with saturated steam |
| B. | Heat is supplied to water at temperature below the maximum temperature of the cycle |
| C. | A Rankine cycle receives heat at two places |
| D. | Rankine cycle is hypothetical |
| Answer» C. A Rankine cycle receives heat at two places | |
| 835. |
_ For reversible adiabatic process, change in entropy is$? |
| A. | Maximum |
| B. | Minimum |
| C. | Zero |
| D. | Negative |
| Answer» D. Negative | |
| 836. |
_ A mixture of gas expands from 0.03 m3 to 0.06 m3 at a constant pressure of 1 MPa and absorbs 84 kJ of heat during the process. The change in internal energy of the mixture is$? |
| A. | 30 kJ |
| B. | 84 kJ |
| C. | 54 kJ |
| D. | 114 kJ |
| Answer» D. 114 kJ | |
| 837. |
_ Charles' law states that all perfect gases change in volume by __________ of its original volume at 0°C for every 1°C change in temperature, when pressure remains constant.$? |
| A. | 1/27th |
| B. | 1/93th |
| C. | 1/173th |
| D. | 1/273th |
| Answer» E. | |
| 838. |
_ The efficiency of a gas turbine is given by$? |
| A. | (Net work output)/(Work-done by the turbine) |
| B. | (Net work output)/(Heat supplied) |
| C. | (Actual temperature drop)/(Isentropic temperature drop) |
| D. | (Isentropic increase in temperature)/(Actual increase in temperature) |
| Answer» C. (Actual temperature drop)/(Isentropic temperature drop) | |
| 839. |
_ A cycle consisting of _________ and two isothermal processes is known as Stirling cycle.$? |
| A. | Two isentropic |
| B. | One constant pressure, one constant volume |
| C. | Two constant volumes |
| D. | Two constant pressures |
| Answer» D. Two constant pressures | |
| 840. |
_ Intensive property of a system is one whose value$? |
| A. | Depends on the mass of the system, like volume |
| B. | Does not depend on the mass of the system, like temperature, pressure, etc. |
| C. | Is not dependent on the path followed but on the state |
| D. | Is dependent on the path followed and not on the state |
| Answer» C. Is not dependent on the path followed but on the state | |
| 841. |
_ An adiabatic process is one in which$? |
| A. | The temperature of the gas changes |
| B. | No heat enters or leaves the gas |
| C. | The change in internal energy is equal to the mechanical work done |
| D. | All of the above |
| Answer» E. | |
| 842. |
_ The more effective way of increasing efficiency of Carnot engine is to$? |
| A. | Increase higher temperature |
| B. | Decrease higher temperature |
| C. | Increase lower temperature |
| D. | Decrease lower temperature |
| Answer» E. | |
| 843. |
_ Specific heat of air at constant pressure is equal to$? |
| A. | 0.17 |
| B. | 0.21 |
| C. | 0.24 |
| D. | 1.0 |
| Answer» D. 1.0 | |
| 844. |
_ The hyperbolic process is governed by$? |
| A. | Avogadro's law |
| B. | Boyle's law |
| C. | Charles' law |
| D. | Gay-Lussac law |
| Answer» C. Charles' law | |
| 845. |
_ The absolute zero pressure can be attained at a temperature of$? |
| A. | 0°C |
| B. | 273°C |
| C. | 273 K |
| D. | None of these |
| Answer» E. | |
| 846. |
_ The basis for measuring thermodynamic property of temperature is given by$? |
| A. | Zeroth law of thermodynamics |
| B. | First law of thermodynamics |
| C. | Second law of thermodynamics |
| D. | Third law of thermodynamics |
| Answer» B. First law of thermodynamics | |
| 847. |
_ A process of heating crude oil to a high temperature under a very high pressure to increase the yield of lighter distillates, is known as$? |
| A. | Cracking |
| B. | Carbonization |
| C. | Fractional distillation |
| D. | Full distillation |
| Answer» B. Carbonization | |
| 848. |
_ In open cycle gas turbine plants$? |
| A. | Direct combustion systems is used |
| B. | A condenser is used |
| C. | The indirect heat exchanger and cooler is avoided |
| D. | All of the above |
| Answer» E. | |
| 849. |
_ The temperature at which the volume of a gas becomes zero is called$? |
| A. | Absolute scale of temperature |
| B. | Absolute zero temperature |
| C. | Absolute temperature |
| D. | None of these |
| Answer» C. Absolute temperature | |
| 850. |
_ The efficiency of a Carnot engine depends on$? |
| A. | Working substance |
| B. | Design of engine |
| C. | Size of engine |
| D. | Temperatures of source and sink |
| Answer» E. | |