1)Which of the following is an example of open system?
Piston-cylinder arrangement during power stroke
Gas turbine
A bottle of cold water exposed to room temperature.
Thermos flask
2)The zeroth law of thermodynamics deals with ………
conversion of heat and work.
reversibility of a process.
concept of thermal equilibrium.
introduction of concept of entropy.
3)Which of the following is not an extensive property?
Entropy
Enthalpy
Internal energy
Density
4)Select the correct statement from the following:
Kaplan turbine is an axial-flow reaction turbine.
Francis turbine is an axial-flow reaction turbine.
Both Pelton and Francis turbines are impulse turbines.
Francis turbine is a reaction turbine but Kaplan turbine is an impulse turbine.
5)Otto cycle consists of which of the following processes?
Two isochoric and two isothermal processes
Two isochoric and two isentropic processes
One isobaric, one isochoric and two isentropic processes
Two isobaric and two isentropic processes
6)Which of the following is a compressible machine?
Hydro turbine
Gas turbine
Pump
Wind turbine
7)In which turbine the pressure head of water is first converted into kinetic energy by means of nozzle kept close to the runner?
Propeller
Francis
Kaplan
Pelton wheel
8)Positive displacement machines (PDMs) work at……….. speed and have ………… volumetric efficiency than non- PDMs.
high, high
low, low
low, high
high, low
9)Choose the INCORRECT statement from the following:
Axial turbine is used to generate large thrust in engines.
The mechanical strength of blades is low for axial flow machines.
High stage pressure ratios can be attained by using radial flow machines.
Radial flow machines experience low amount of drag force.
10)Air at 100 kPa and 298 K is compressed to 500 kPa and 450 K. Mass flows through the compressor at the rate of 0.05 kg/s and heat lost during compression is 20 kJ/kg. Consider the change in kinetic and potential energy to be negligible during compression and find the power input required for compression. (Cp = 1.005 kJ/kgK)
5.18 kW
3.98 kW
4.58 kW
5.78 kW
11) Air at 90 kPa and 24 degrees Celsius enters an adiabatic diffuser steadily with velocity 190 m/s and leaves with a low velocity at a pressure of 130 kPa. The inlet area of diffuser is 0.5 sq. m. Find mass flow rate (kg/s) and the exit temperature (K) of air, respectively. (Cp = 1.005 kJ/kgK, R= 287 J/kgK)
85, 42
100, 35
85, 35
100, 42
12) An adiabatic nozzle having an inlet to exit area ratio of 3:1 takes in air at 550 kPa and 480 K. The air enters and leaves the nozzle with velocities of 100 m/s and 350 m/s respectively. Determine the exit pressure and temperature , respectively (Cp = 1.005 kJ/kgK, R = 287 J/kgK)
46 kPa, 468 K
416 kPa, 412 K
416 kPa, 424 K
46 kPa, 380 K