The internal energy of a substance can be increased by
a. doing work on it
b. letting it do work
c. adding heat to it
d. extracting heat from it
e. none of the above
[Ques. 2] The internal energy of air can be increased by
a. compressing it c. lifting it
b. allowing heat to flow into it d. allowing it to expand
[Ques. 3] Solar energy
a. is a recent invention
b. has been used for a long time
c. has not yet been successfully developed
d. is indirectly the source of most of the energy we use
[Ques. 4] Stepping barefoot off a rug onto a hardwood floor makes your feet feel cold. Why?
a. The hardwood floor is at a lower temperature than the rug.
b. The hardwood floor is at a lower temperature than your feet.
c. The hardwood floor conducts heat away from your feet better than the rug.
d. all of the above
[Ques. 5] Absolute zero is
a. 0 K c. 273.15C
b. 459.67F d. 0 on any temperature scale.
[Ques. 6] Heat transfer by radiation occurs via
a. electromagnetic waves
b. nuclear decay
c. molecular collisions
d. the solar wind
e. none of the above
[Ques. 7] A piston compresses a gas, while at the same time heat is lost to the surroundings. The temperature of the gas rises. The amount of temperature rise is governed by
a. the first law of thermodynamics
b. the second law of thermodynamics
c. specific heat capacity
d. a heat pump
e. none of the above
[Ques. 8] The efficiency of a heat engine
a. can never exceed the Carnot efficiency
b. can be improved by lowering the temperature of the cool reservoir
c. can be improved by raising the temperature of the hot reservoir
d. all of the above
[Ques. 9] In a steam engine, steam at 140C in a turbine does work on an external system, and the steam leaves the turbine at 100C. The efficiency of the steam engine is 5. The relevant physical principle is
a. the first law of thermodynamics
b. the second law of thermodynamics
c. specific heat capacity
d. operation of a heat pump
e. none of the above
[Ques. 10] Even when the temperature of a pan of water is below the boiling point, some water still evaporates. This is because
a. of convection
b. the kinetic energies of individual water molecules vary above and below the average value
c. the humidity always increases
d. none of the above