GATE XE topic:engineering PYQs & Answers — Page 169

Questions 1681–1690 of 1772. Imported answers require independent review unless marked reviewed.

Given the thermodynamic function relations:

and

, the term

is equal to

Your answerChoose one option.

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Two closed cycle gas turbine engines, A and B, operate on air standard Brayton cycle with efficiencies of

and

, respectively. If they operate between the same maximum and minimum temperatures, but with different pressure ratios of

and

, (

), then,

Your answerChoose one option.

cannot be determined as the efficiencies are maximum only at the optimal

values.

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The values of density and isentropic compressibility of water at certain pressure and temperature are given as 1000 kg/m³ and

Pa⁻¹, respectively. The speed at which sound travels in water under these conditions in m/s is equal to ________.

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Length of a certain metal rod at 0°C is 10 cm. The coefficient of linear expansion of that metal varies with temperature as

(cm/cm)/°C. When the length of the metal rod is 10.2 cm, the rise in temperature in °C is ________.

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In a polytropic compression process, one kg of an ideal gas having a molecular weight of 40 kg/kmol is compressed from 100 kPa, 300 K to 400 kPa, 360 K. The magnitude of the work in kJ for the process is

Your answerChoose one option.

52.3

62.3

72.3

82.3

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Two streams of air (

J/kg.K) flow through insulated pipes 1 and 2 with the conditions as shown in figure. They mix in an insulated pipe-3 and the mixture steadily exits with a velocity of 100 m/s at 150 kPa. Neglecting the change in potential energy in all the pipes, the exit area of the pipe-3 in m² (up to 3 decimal places) is ________.

Diagram for Engineering Sciences question 89

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A 1 m³ rigid vessel contains air at 200 kPa. A vacuum pump is connected to the vessel in order to control the pressure inside. The volume flow rate of air through the pump is maintained at a constant value of 0.1 m³/s. If the pump operates for 10 seconds and the temperature of the air is maintained constant during operation, the pressure in the tank in kPa after 10 seconds (up to 2 decimal places) is ________.

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A heat engine receives

kJ of heat from a hot reservoir and rejects

kJ of heat to a cold reservoir. The work delivered by the heat engine is entirely supplied to a heat pump, which receives

kJ of heat from another reservoir and rejects

kJ of heat to the same cold reservoir. If the efficiency of the heat engine is 0.4 and COP of the heat pump is 4.0, the value of

(up to 1 decimal place) is _________.

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A block of ice of mass 2 kg at 0°C is dropped into an insulated vessel containing 10 kg of liquid water at 25°C. The latent heat of melting of ice is 330 kJ/kg and specific heat of water is 4.2 kJ/kg.K. The change in the entropy of the universe in kJ/K (up to 3 decimal places) is _________.

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A pure substance (

= 0.733 kJ/kg.K) undergoes a reversible process in which its temperature increases linearly from 40°C to 85°C and its specific entropy increases by 600 J/kg.K. The work done by the system in kJ/kg is

Your answerChoose one option.

160.2

164.3

168.3

172.3

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GATE XE topic:engineering PYQs

Question 84

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Question 88

Question 89

Question 90

Question 91

Question 92

Question 93