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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.
| 851. |
_ The heat flows from a cold body to a hot body with the aid of an external source. This statement is given by$? |
| A. | Kelvin |
| B. | Joule |
| C. | Clausis |
| D. | Gay-Lussac |
| Answer» D. Gay-Lussac | |
| 852. |
_ The change of entropy, when heat is absorbed by the gas, is$? |
| A. | Positive |
| B. | Negative |
| C. | Positive or negative |
| D. | None of these |
| Answer» B. Negative | |
| 853. |
_ Calorie is a measure of$? |
| A. | Specific heat |
| B. | Quantity of heat |
| C. | Thermal capacity |
| D. | Entropy |
| Answer» C. Thermal capacity | |
| 854. |
__The pressure of a gas in terms of its mean kinetic energy per unit volume 'E' is equal to__ |
| A. | E/3 |
| B. | E/2 |
| C. | 3E/4 |
| D. | 2E/3 |
| Answer» E. | |
| 855. |
__The compression ratio for Diesel engines is__ |
| A. | 15 to 20 |
| B. | 5 to 8 |
| C. | 3 to 6 |
| D. | 20 to 30 |
| Answer» B. 5 to 8 | |
| 856. |
__Carnot cycle consists of__ |
| A. | Two constant volume and two isentropic processes |
| B. | Two isothermal and two isentropic processes |
| C. | Two constant pressure and two isentropic processes |
| D. | One constant volume, one constant pressure and two isentropic processes |
| Answer» C. Two constant pressure and two isentropic processes | |
| 857. |
__Coke is produced__ |
| A. | When coal is strongly heated continuously for 42 to 48 hours in the absence of air in a closed vessel |
| B. | From the finely ground coal by moulding under pressure with or without a binding material |
| C. | When coal is first dried and then crushed to a fine powder by pulverizing machine |
| D. | By heating wood with a limited supply of air to a temperature not less than 280°C |
| Answer» B. From the finely ground coal by moulding under pressure with or without a binding material | |
| 858. |
__One kg of carbon requires 4/3 kg of oxygen and produces __________ kg of carbon monoxide gas.__ |
| A. | 8/3 |
| B. | 11/3 |
| C. | 11/7 |
| D. | 7/3 |
| Answer» E. | |
| 859. |
__Which of the following has the minimum atomic mass?__ |
| A. | Sulphur |
| B. | Nitrogen |
| C. | Oxygen |
| D. | Carbon |
| Answer» E. | |
| 860. |
__According to Dalton's law, the total pressure of the mixture of gases is equal to__ |
| A. | Greater of the partial pressures of all |
| B. | Average of the partial pressures of all |
| C. | Sum of the partial pressures of all |
| D. | Sum of the partial pressures of all divided by average molecular weight |
| Answer» D. Sum of the partial pressures of all divided by average molecular weight | |
| 861. |
__The fuel mostly used in blast furnace for extracting pig iron from iron ores is__ |
| A. | Hard coke |
| B. | Soft coke |
| C. | Pulverized coal |
| D. | Bituminous coal |
| Answer» B. Soft coke | |
| 862. |
__The index of compression ‘n’ tends to reach ratio of specific heats ‘y’ when__ |
| A. | Flow is uniform and steady |
| B. | Process is isentropic |
| C. | Process is isothermal |
| D. | Process is isentropic and specific heat does not change with temperature |
| Answer» E. | |
| 863. |
__One molecule of oxygen is __________ times heavier than the hydrogen atom.__ |
| A. | 12 |
| B. | 14 |
| C. | 16 |
| D. | 32 |
| Answer» E. | |
| 864. |
__The ratio of two specific heats of air is equal to__ |
| A. | 0.17 |
| B. | 0.24 |
| C. | 0.1 |
| D. | 1.41 |
| Answer» E. | |
| 865. |
__For which of the following substances, the gas laws can be used with minimum error__ |
| A. | Dry steam |
| B. | Wet steam |
| C. | Saturated steam |
| D. | Superheated steam |
| Answer» E. | |
| 866. |
__The unit of energy is S. I. units is__ |
| A. | Joule (J) |
| B. | Joule meter (Jm) |
| C. | Watt (W) |
| D. | Joule/meter (J/m) |
| Answer» B. Joule meter (Jm) | |
| 867. |
__An isolated system is one in which__ |
| A. | Mass does not cross boundaries of the system, though energy may do so |
| B. | Neither mass nor energy crosses the boundaries of the system |
| C. | Both energy and mass cross the boundaries of the system |
| D. | Mass crosses the boundary but not the energy |
| Answer» C. Both energy and mass cross the boundaries of the system | |
| 868. |
__Boyle's law i.e. pV = constant is applicable to gases under__ |
| A. | All ranges of pressures |
| B. | Only small range of pressures |
| C. | High range of pressures |
| D. | Steady change of pressures |
| Answer» C. High range of pressures | |
| 869. |
__Which of the following statement is correct according to Clausis statement of second law of thermodynamics?__ |
| A. | It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature. |
| B. | It is impossible to transfer heat from a body at a lower temperature to a body at a higher temperature, without the aid of an external source. |
| C. | It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature by using refrigeration cycle. |
| D. | None of the above |
| Answer» C. It is possible to transfer heat from a body at a lower temperature to a body at a higher temperature by using refrigeration cycle. | |
| 870. |
__Work-done during adiabatic expansion is given by (where p1 v1, T1 = Pressure, volume and temperature for the initial condition of gas, p2, v2, T2 = Corresponding values for the final condition of gas, R = Gas constant, and γ = Ratio of specific heats)__ |
| A. | (p1 v1 - p2, v2)/(γ - 1) |
| B. | [m R (T1 - T2)] /(γ - 1) |
| C. | [m R T1/(γ - 1)][1 - (p2, v2 /p1 v1)] |
| D. | All of these |
| Answer» E. | |
| 871. |
__The unit of mass in S.I. units is__ |
| A. | Kilogram |
| B. | Gram |
| C. | Tonne |
| D. | Quintal |
| Answer» B. Gram | |
| 872. |
_Which of the following gas is mostly used in town for street and domestic lighting and heating?$? |
| A. | Mond gas |
| B. | Coal gas |
| C. | Producer gas |
| D. | Coke oven gas |
| Answer» C. Producer gas | |
| 873. |
_Which of the following quantities is not the property of the system?$? |
| A. | Pressure |
| B. | Temperature |
| C. | Specific volume |
| D. | Heat |
| Answer» E. | |
| 874. |
_In a reversible adiabatic process, the ratio of T1/T2 is equal to$? |
| A. | (p2/p1)γ - 1/ γ |
| B. | (p1/p2)γ - 1/ γ |
| C. | (v2/v1)γ - 1/ γ |
| D. | (v1/v2)γ - 1/ γ |
| Answer» C. (v2/v1)≈í‚â• - 1/ ≈í‚â• | |
| 875. |
_When the gas is heated at constant pressure, the heat supplied$? |
| A. | Increases the internal energy of the gas |
| B. | Increases the temperature of the gas |
| C. | Does some external work during expansion |
| D. | Both (B) and (C) |
| Answer» E. | |
| 876. |
_Work done in an adiabatic process between a given pair of end states depends on$? |
| A. | The end states only |
| B. | Particular adiabatic process |
| C. | The value of index ‘n’ |
| D. | The value of heat transferred |
| Answer» B. Particular adiabatic process | |
| 877. |
_Carbonization of coal consists of$? |
| A. | Drying and crushing the coal to a fine powder |
| B. | Moulding the finely ground coal under pressure with or without a binding material |
| C. | Heating the wood with a limited supply of air to temperature not less than 280°C |
| D. | None of the above |
| Answer» E. | |
| 878. |
_The amount of heat generated per kg of fuel is known as$? |
| A. | Calorific value |
| B. | Heat energy |
| C. | Lower calorific value |
| D. | Higher calorific value |
| Answer» B. Heat energy | |
| 879. |
_The entropy may be expressed as a function of$? |
| A. | Pressure and temperature |
| B. | Temperature and volume |
| C. | Heat and work |
| D. | All of these |
| Answer» B. Temperature and volume | |
| 880. |
_Otto cycle is also known as$? |
| A. | Constant pressure cycle |
| B. | Constant volume cycle |
| C. | Constant temperature cycle |
| D. | Constant temperature and pressure cycle |
| Answer» C. Constant temperature cycle | |
| 881. |
_In an isothermal process, the internal energy of gas molecules$? |
| A. | Increases |
| B. | Decreases |
| C. | Remain constant |
| D. | May increase/decrease depending on the properties of gas |
| Answer» D. May increase/decrease depending on the properties of gas | |
| 882. |
_The unit of temperature in S.I. units is$? |
| A. | Centigrade |
| B. | Celsius |
| C. | Fahrenheit |
| D. | Kelvin |
| Answer» E. | |
| 883. |
_For which of the following substances, the internal energy and enthalpy are the functions of temperature only$? |
| A. | Any gas |
| B. | Saturated steam |
| C. | Water |
| D. | Perfect gas |
| Answer» E. | |
| 884. |
_Carnot cycle efficiency is maximum when$? |
| A. | Initial temperature is 0°K |
| B. | Final temperature is 0°K |
| C. | Difference between initial and final temperature is 0°K |
| D. | Final temperature is 0°C |
| Answer» C. Difference between initial and final temperature is 0¬¨‚àûK | |
| 885. |
_Minimum work in compressor is possible when the value of adiabatic index ‘n’ is equal to$? |
| A. | 0.75 |
| B. | 1 |
| C. | 1.27 |
| D. | 1.35 |
| Answer» C. 1.27 | |
| 886. |
_In closed cycle gas turbine, the air is compressed$? |
| A. | Isothermally |
| B. | Isentropically |
| C. | Polytropically |
| D. | None of these |
| Answer» C. Polytropically | |
| 887. |
_The throttling process is __________ process.$? |
| A. | Reversible |
| B. | Irreversible |
| C. | Reversible or irreversible |
| D. | None of these |
| Answer» C. Reversible or irreversible | |
| 888. |
_A manufacturer claims to have a heat engine capable of developing 20 h.p. by receiving heat input of 400 kcal/mt and working between the temperature limits of 227° C and 27° C. His claim is$? |
| A. | Theoretically possible |
| B. | Not possible |
| C. | May be possible with lot of sophistications |
| D. | Cost will be very high |
| Answer» C. May be possible with lot of sophistications | |
| 889. |
_The specific heat of air increases with increase in$? |
| A. | Temperature |
| B. | Pressure |
| C. | Both pressure and temperature |
| D. | Variation of its constituents |
| Answer» B. Pressure | |
| 890. |
_A cycle consisting of one constant pressure, one constant volume and two isentropic processes is known as$? |
| A. | Otto cycle |
| B. | Stirling cycle |
| C. | Carnot cycle |
| D. | Diesel cycle |
| Answer» E. | |
| 891. |
_The atomic mass of oxygen is$? |
| A. | 14 |
| B. | 16 |
| C. | 18 |
| D. | 121 |
| Answer» C. 18 | |
| 892. |
_The heat supplied to the gas at constant volume is (where m = Mass of gas, cv = Specific heat at constant volume, cp = Specific heat at constant pressure, T2 - T1 = Rise in temperature, and R = Gas constant)$? |
| A. | mR (T2 - T1) |
| B. | mcv (T2 - T1) |
| C. | mcp (T2 - T1) |
| D. | mcp (T2 + T1) |
| Answer» C. mcp (T2 - T1) | |
| 893. |
_Which of the following processes is irreversible process?$? |
| A. | Isothermal |
| B. | Adiabatic |
| C. | Throttling |
| D. | All of the above |
| Answer» D. All of the above | |
| 894. |
_Work-done in a free expansion process is$? |
| A. | Zero |
| B. | Minimum |
| C. | Maximum |
| D. | Positive |
| Answer» B. Minimum | |
| 895. |
_The value of n = 1 in the polytropic process indicates it to be$? |
| A. | Reversible process |
| B. | Isothermal process |
| C. | Adiabatic process |
| D. | Irreversible process |
| Answer» C. Adiabatic process | |
| 896. |
_In order that a cycle be reversible, following must be satisfied$? |
| A. | Free expansion or friction resisted expansion/compression process should not be encountered |
| B. | When heat is being absorbed, temperature of hot source and working substance should be same |
| C. | When beat is being rejected, temperature of cold source and working substance should be same |
| D. | All of the above |
| Answer» E. | |
| 897. |
_Which of the following is an intensive property of a thermodynamic system?$? |
| A. | Mass |
| B. | Temperature |
| C. | Energy |
| D. | Volume |
| Answer» C. Energy | |
| 898. |
_The specific heat at constant volume is$? |
| A. | The amount of heat required to raise the temperature of unit mass of gas through one degree, at constant volume |
| B. | The amount of heat required to raise the temperature of unit mass of gas through one degree, at constant pressure |
| C. | The amount of heat required to raise the temperature of 1 kg of water through one degree |
| D. | Any one of the above |
| Answer» B. The amount of heat required to raise the temperature of unit mass of gas through one degree, at constant pressure | |
| 899. |
_According to Clausius statement of second law of thermodynamics$? |
| A. | Heat can |
| B. | Heat can be transferred for low temperature to high temperature source by using refrigeration cycle |
| C. | Heat can be transferred from low temperature to high temperature source if COP of process is more than unity |
| D. | Heat can |
| Answer» E. | |
| 900. |
_The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and re-condensed, then the liquid with the next higher boiling point is then evaporated and re-condensed, and so on until all the available liquid fuels are separately recovered in the sequence of their boiling points. Such a process is called$? |
| A. | Cracking |
| B. | Fractional distillation |
| C. | Full distillation |
| D. | Carbonisation |
| Answer» C. Full distillation | |