1. An automobile tire is inflated to 32 psig pressure at 50°F. After being driven, the temperature rises to 75°F. Assuming that the volume remains constant, the final gage pressure is:
a. 34.3 psig
b. 37.4 psig
c. 39.4 psig
d. 46.7 psig
e. 48.8 psig
2. What is the temperature of 2 liters of water at 30°C after 500 calories of heat have been added to it?
a. 23.50°C
b. 25.30°C
c. 30.25°C
d. 35.20°C
e. 38.25°C
3. The maximum thermal efficiency possible for a power cycle operating between 1200°F and 225°F is:
a. 57.00%
b. 57.50%
c. 57.54%
d. 58.00%
e. 58.73%
4. The atmospheric pressures at the top and bottom of a building are read by a barometer to be 96.0 and 98.0 kPa. If the density of air is 1.2 kg/m3, the height of the building is:
a. 14 m
b. 17 m
c. 142 m
d. 170 m
e. 210 m
5. A rigid tank contains 5 kg of an ideal gas at 4 atm and 40°C. Now a valve is opened, and half of mass of the gas is allowed to escape. If the final pressure in the tank is 1.5 atm, the final temperature in the tank is
a. –38°C
b. 30°C
c. 40°C
d. 53°C
e. 144°C
6. A 1-m3 rigid tank contains 10 kg of water (in any phase or phases) at 150°C. The pressure in the tank is
a. 500 kPa
b. 475.8 kPa
c. 270.1 kPa
d. 1,000 kPa
e. 1,618 kPa
7. Water is boiled in a pan on a stove at sea level. During 10 min of boiling, it is observed that 200 g of water has evaporated. Then the rate of heat transfer to the water is
a. 0.84 kJ/min
b. 41.8 kJ/min
c. 45.1 kJ/min
d. 53.5 kJ/min
e. 225.7 kJ/min
8. A 5-m3 rigid vessel contains steam at 20 MPa and 400°C. The mass of the steam is
a. 0.322 kg
b. 5 kg
c. 322 kg
d. 503 kg
e. 680 kg
9. A 2-m3 rigid tank contains nitrogen gas at 500 kPa and 300 K. Now heat is transferred to the nitrogen in the tank and the pressure of nitrogen rises to 800 kPa. The work done during this process is
a. 0 kJ
b. 500 kJ
c. 600 kJ
d. 1,000 kJ
e. 1,600 kJ
10. A piston-cylinder initially contains 0.4 m3 air at 100 kPa and 80°C. The air is then compressed to 0.1 m3 in such a way that the temperature inside the cylinder remains constant. Determine the work done during the process.
a. 32.3 kJ
b. 40.0 kJ
c. 55.4 kJ
d. 105.9 kJ
e. 373.2 kJ
11. The walls of a cold storage plant are composed of an insulating material (k=0.2336 kJ/hr.m.°C) 10.16 cm thick held between two layers of concrete (k=3.7382 kJ/hr.m.°C) each 10.16 cm thick. The film coefficients are 81.76 kJ/hr.m2.C on the outside and 40.88 kJ/hr.m2.°C on the inside. Cold storage temperature is -6.7°C and the ambient temperature is 32.2°C. Determine the heat transmitted in kW through an area of 55.74 m2.
a. 1.14 kW
b. 1.25 kW
c. 1.74 kW
d. 1.81 kW
e. 1.95 Kw
12. A 12 in thick furnace wall with a dimension of 5 m by 2 m has a temperature difference of 60°C. The wall has a thermal conductivity of 0.75 Btu/hr.ft.°F. Calculate the heat transmitted across the wall
a. 2440 W
b. 2445 W
c. 2455 W
d. 2545 W
e. 2554 W
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