GATE PI topic:thermal-fluids-engineering PYQs & Answers — Page 2

Questions 11–20 of 39. Imported answers require independent review unless marked reviewed.

Under steady state conditions, superheated steam enters the turbine with enthalpy, h

= 3200 kJ/kg and wet steam leaves the turbine at pressure

= 0.1 bar. The heat loss is 100 kJ/kg and work output is 100 kJ/kg. Kinetic and potential energies for inflow and outflow are neglected. At pressure 0.1 bar, the enthalpy of saturated liquid is 200 kJ/kg and the enthalpy of vaporization is 2400 kJ/kg. The dryness fraction of the steam at the exit of the turbine is _____ (round off to 2 decimal places).

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Water flows through a pipe of diameter 0.02 m. The Reynolds number of the flow is 100. The pipe is heated from outside with a uniform heat flux. The flow and heat transfer in the pipe are steady and fully developed. The thermal conductivity of water is 0.66 W/(m-K). The convective heat transfer coefficient, in W/(m²-K), is _____ (round off to 2 decimal places).

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

In an ideal air-standard Brayton cycle, air enters the compressor at 100 kPa and 300 K. Thermal efficiency of the cycle is 50 %. The heat added to air is 100 kJ/kg. Air has constant specific heat

kJ/(kg-K) and

. Air temperature, in K, at the turbine inlet is _____ (round off to 2 decimal places).

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Water (kinematic viscosity

) is flowing through a circular horizontal pipe of diameter 8 mm. If the flow is laminar and fully developed with a maximum axial velocity of 0.5 m/s, the Reynolds number is____________. [round off to nearest integer]

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Air at an initial temperature and pressure of 15 °C and 1 bar, respectively is heated in an irreversible process. The final temperature and pressure are 303 °C and 2 bar, respectively. Take gas constant for air as R = 287 J/kg-K, the ratio of the specific heats as γ = 1.4, and treat air as a calorically perfect gas. The change of entropy (in J/kg-K) in the process is____________. [round off to nearest integer]

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The dimensionless number defined by the ratio of inertial force to viscous force is called

Your answerChoose one option.

Mach number

Froude number

Weber number

Reynolds number

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A small capillary tube of 3 mm inner diameter is inserted into a fluid having density 900 kg/m

, surface tension 0.1 N/m, and contact angle 30°. The rise in the height of fluid in the capillary tube due to surface tension is

Your answerChoose one option.

11.4 mm

128.3 mm

89.1 mm

154.1 mm

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Heat is being removed from a refrigerator at a rate of 300 kJ/min to maintain its inside temperature at 2 °C. If the input power to the refrigerator is 2 kW, the coefficient of performance of the refrigerator is ____________. [round off to one decimal place]

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

In an ideal Otto cycle, 800 kJ/kg is transferred to air during the constant volume heat addition process and 381 kJ/kg is removed during the constant volume heat rejection process. The thermal efficiency in % of the cycle is ____________. [round off to one decimal place]

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A circular tank of 4 m diameter is filled up to a height of 3 m. Assuming almost steady flow and neglecting losses, the time taken in seconds to empty the tank through a 5 cm diameter hole located at the center bottom (take acceleration due to gravity g = 9.81 m/s²) is [round off to the nearest integer]

Your answerChoose one option.

505

187

897

354

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE PI topic:thermal-fluids-engineering PYQs

Question 32

Question 60

Question 61

Question 27

Question 48

Question 16

Question 17

Question 22

Question 23

Question 36