Time Left - 15:00 mins
GATE 2019: Thermodynamics Rapid Quiz-2
Attempt now to get your rank among 554 students!
Question 1
Heat transfer (in kJ/kg) for the reversible steady flow process 1 - 3 shown in figure below is _________ (kJ/kg).
Question 2
The temperature limits of an ammonia refrigerating system are 30 °C and –10 °C. If the gas is dry saturated at the end of compression and there is no undercooling of liquid ammonia, the COP of the cycle is:
Use the following table for the properties of ammonia:
Use the following table for the properties of ammonia:
Question 3
5 m3 of an ideal gas at 1 bar pressure is compressed isothermally in an adiabatic piston-cylinder device to 2 m3. Maximum work input needed by the compressor is
Question 4
A freezing plant requires 50 tons of refrigeration. The freezing temperature is – 33 °C and ambient temperature is 27 °C. If the performance of the plant is one-third of the theoretical reversed Carnot cycle working between the same temperature limits, the power input (in kW) required for the plant is
Question 5
A cool room of a ship whose inner dimensions are 12 m × 2.3 m × 3.5 m is to be precooled from 25 °C to an average temperature of 5 °C. The location of the cool room is such that a transmission heat gain occurs at a rate of 40 W/ °C. If the ambient temperature is 25 °C, then how much time (in min) it will take for a system with a refrigeration capacity of 8 kW to precool this room?
[Take ρair = 1.2 kg/m3 and (Cp)air = 1.005 kJ/kgK]
[Take ρair = 1.2 kg/m3 and (Cp)air = 1.005 kJ/kgK]
Question 6
A gas expands from pressure 
to pressure 
If the expansion process is isothermal, the volume at the end of expansion is 0.5 m3. If the expansion process is adiabatic(take final pressure same as in case of isothermal process), the volume (in m3) at the end of expansion will be closer to
[Take
for gas = 1.4]
to pressure If the expansion process is isothermal, the volume at the end of expansion is 0.5 m3. If the expansion process is adiabatic(take final pressure same as in case of isothermal process), the volume (in m3) at the end of expansion will be closer to [Take
for gas = 1.4] Question 7
The gear box of a machine is operating under steady state. The input shaft receives 55 kW from a prime mover and transmits 52 kW to the output shaft, the rest being lost due to friction etc. The gear box surface is at an average temp. of 57 °C and looses heat to the surroundings at 27 °C. The rate of entropy production (W/K) inside the gear box is
Question 8
A piston cylinder device contains 0.05 m3 of gas initially at 180 kPa. At this state, a linear spring that has a spring constant of 150 kN/m is just touching the piston but exerting no force on it. Now heat is transferred to the gas, causing the piston to rise and to compress the spring until the volume inside the cylinder doubles. If the cross-sectional area of the piston is 0.25 m2, then the total work done (in kJ) by the gas will be
Question 9
Considering steady heat transfer through a 10 m × 15 m brick wall of a house of thickness 50 cm. On a day when the temperature of the outdoors is 7 °C and the indoor temperature is maintained at 27 °C. the temperature of the inner and outer surfaces of the brick wall are measured to be 25 °C and 9 °C, respectively, and the rate of heat transfer through the wall is 1500 watt. Rate of total entropy generation associated with this heat transfer process is ________ W/K.
Question 10
A spherical ballon has a diameter of 25 cm and contains air at pressure of 150 kPa. The diameter Of the ballon increases to 30 cm in certain process. During this process the pressure of gas inside the balloon is proportional to the diameter of the ballon. What is the work done by the air inside the balloon during this process ?
Question 11
An ideal gas is heated at constant volume until its temperature is doubled and then cooled at constant pressure until it returned to original temperature.
Finally the gas is allowed to expand at constant temperature until it is returned to the original volume.Expression to determine the net work done by the gas is [Take m = 1 kg]
Finally the gas is allowed to expand at constant temperature until it is returned to the original volume.Expression to determine the net work done by the gas is [Take m = 1 kg]
Question 12
An automobile engine operates at a fuel air ratio of 0.05, volumetric efficiency of 90% and indicated thermal efficiency of 30%. Given that the calorific value of the fuel is 45 MJ/kg and the density of air at intake is 1 kg/m3, the indicated mean effective pressure for the engine is
- 554 attempts
- 4 upvotes
- 1 comment
Feb 16ESE & GATE ME
