GATE XE topic:engineering PYQs & Answers — Page 11

Questions 101–110 of 1772. Imported answers require independent review unless marked reviewed.

Topic practice 1772 questionsPage 11 of 178

An adiabatic rigid and impermeable tank of volume

contains air at 800 kPa and 70 °C. The air is allowed to leave the tank until the pressure is one-fourth of its original value. During the process, the air in the tank is maintained at 70 °C using an electrical heater. Assume that the air behaves as an ideal gas having gas constant and ratio of specific heat capacities as 287 J/kg-K and 1.4, respectively. The total electrical energy (in MJ) supplied by the heater is ____________ (rounded off to two decimal places).

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Two kg of a gas is compressed in a process. Pressure (P) and mass specific volume (v) of the gas during the process follows:

. The temperature of the gas before and after compression is 300 K and 600 K, respectively. Assume that the gas behaves as an ideal gas with gas constant and ratio of specific heat capacities equal to 287 J/kg-K and 1.4, respectively. The heat rejected (in kJ) during the process is ____________ (rounded off to two decimal places).

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Consider a single component fluid at saturation conditions having the following properties.

Latent heat of vaporization,

kJ/kmol

Compressibility factor for the vapor phase,

is the saturation pressure

is the temperature

is the molar specific volume of the vapor phase

Assume that

, where

is the difference in the molar specific volume of the vapor and the liquid phases

Universal gas constant,

kJ/kmol-K

Using the Clapeyron equation, the quantity

(in K) is ________ (rounded off to two decimal places).

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It is given that:

and

. Here

is the mass specific enthalpy,

is the mass specific volume,

is the volume expansivity, and

is the mass specific heat capacity at constant pressure.

and

represent the temperature and the pressure, respectively. The inversion temperature is the temperature at which the Joule-Thomson coefficient,

, goes to zero.

Consider a fluid with properties:

/kg,

kJ/kg-K, and

1/K;

The inversion temperature (in K) for the fluid is ________ (rounded off to two decimal places).

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A stream of moist air enters an adiabatic saturator at 45 °C and 101 kPa and leaves as a saturated mixture at 30 °C. Make-up water to the saturator is supplied at 30 °C. The amount of make-up water (in grams per kg of dry air) supplied is __________ (rounded off to two decimal places).

Use the following data:

Specific heat capacity of water is 4.2 kJ/kg-K

Specific heat capacity of air at constant pressure is 1 kJ/kg-K

Saturated water properties:

At 30 °C: specific enthalpy of saturated water vapor is 2556 kJ/kg-K, specific enthalpy of saturated liquid water is 125.7 kJ/kg-K, and saturation pressure is 4.25 kPa

At 45 °C: specific enthalpy of saturated water vapor is 2582 kJ/kg-K, specific enthalpy of saturated liquid water is 188.4 kJ/kg-K, and saturation pressure is 9.60 kPa

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A rigid spherical solid ball at 100 °C is cooled slowly to 200 °C in a surrounding air at 25 °C. The density, specific heat capacity, and diameter of the ball are 800 kg/m³, 500 J/kg-K, and 10 mm; respectively. Assuming that the cooling process is quasi-equilibrium, the entropy generated (in J/K) in the process is ____________ (rounded off to two decimal places).

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Consider an ideal Diesel-cycle with cold-air-standard assumptions to be applicable. The compression ratio is 20 and the cut-off ratio is 1.8. At the end of the compression process, the working fluid is at 1120 K and 6.6 MPa. The ratio of the specific heat capacities is 1.4 for the working fluid. The temperature (in K) at the end of the expansion process is ____________ (rounded off to two decimal places).

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A mixture of helium (He) and nitrogen (N₂) expands in a turbine from 800 kPa to 100 kPa. The mixture composition is 40% He and 60% N₂ by mass. The turbine inlet temperature is 1000 K. The temperature (in K) at the turbine exit is ____________ (rounded off to two decimal places).

Assume:

The process is isentropic. Kinetic and potential energy changes in the process are negligible. He and N₂ behaves as ideal gases. Specific heat capacities are constant.

Use the following data:

Ratio of specific heat capacities for He and N₂ are 1.67 and 1.4, respectively.

Specific heat capacities at constant pressure for He and N₂ are 5.19 kJ/kg-K and 1.04 kJ/kg-K, respectively.

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A rigid and impermeable tank has only moist air with a specific humidity of 0.025 kgwater-vapor/kgdry-air at 30 °C and 101 kPa. The air is heated to 90 °C. Assume moist air to behave as an ideal gas. The relative humidity (in %) of the heated air is ____________ (rounded off to two decimal places).

Saturation pressure of water at 30 °C is 4.25 kPa and at 90 °C is 70.18 kPa.

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Which one of the following polymerization methods is used for the synthesis of butyl rubber?

Your answerChoose one option.

Ring opening polymerization

Condensation polymerization

Cationic polymerization

Anionic polymerization

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GATE XE topic:engineering PYQs

Question 101

Question 102

Question 103

Question 104

Question 105

Question 106

Question 107

Question 108

Question 109

Question 110