True-false questions are worth 2 points each, three-choice multiple choice questions are worth 3 points each, five-choice multiple choice questions are worth 6 points each. The maximum possible score is 171.

(a) 0.09 W (b) 0.18 W (c) 300 W (d) 0.0009 W (e) 0.015 W

(a) 3.7 J (b) 37 J (c) 370 J (d) 3700 J (e) 37000 J

(a) 5 × 10^{-11} (b) 0.40 (c) 0.60 (d) 10^{-301} (e) 0.0

(a) Δσ = 6.91 (b) Δσ = 3.45 (c) Δσ = 3.97 (d) Δσ = 3.58 (e) Δσ = 2.30

(a) 339°C (b) 612°C (c) 877°C

(a) 1 nm (b) 1 micron (c) 1 mm (d) 1 meter (e) 10 meters

(a) (b) (c)

(a) 7.8 × 10^{-19} J (b) 5.1 × 10^{-20} J (c) 5.1 × 10^{20} J (d) 4.1 × 10^{-21} J (e) 6.2 × 10^{-21} J

Suppose that the heat flow out of your 20°C house is 2 kW. If the temperature outside is -5°C, how much power would an ideal heat pump require to keep the inside of your house at 20°C?

(a) 12.4 W (b) 36.6 W (c) 171 W (d) 2 kW (e) 3.7 kW

(a) ΔS = -1.6 J/K (b) ΔS = -0.5 J/K (c) ΔS = 1.3 J/K (d) ΔS = 2.7 J/K (e) Not enough information is given.

(a) ΔS = 2.54 J/K (b) ΔS = 7.63 J/K (c) ΔS = 10.23 J/K (d) ΔS = 15.27 J/K (e) ΔS = 28.94 J/K

Define:

ΔS_{H} = change in entropy of the hot reservoir in one cycle ΔS_{C} = change in entropy of the cold reservoir in one cycle ΔS_{E} = change in entropy of the engine in one cycle

(a) | ΔS_{E} | = 0, | ΔS_{H} | > | ΔS_{C} | (b) | ΔS_{E} | = 0, | ΔS_{H} | < | ΔS_{C} | (c) | ΔS_{E} | > 0, | ΔS_{H} | > | ΔS_{C} | (d) | ΔS_{E} | > 0, | ΔS_{H} | < | ΔS_{C} | (e) | ΔS_{E} | > 0, | ΔS_{H} | = | ΔS_{C} |

A brick with constant heat capacity C = 3 J/K is heated to 120°C and connected to one side of a Carnot engine; the other side is kept at a constant temperature of 20°C.

How much total work can be extracted from the brick?

(a) W = 41.9 J (b) W = 54.6 J (c) W = 75.2 J (d) W = 103.5 J (e) W = 134.2 J

(a) ΔS_{TOT} > 0 (b) ΔS_{TOT} = 0 (c) ΔS_{TOT} < 0

(a) The entropy of the small system is maximized. (b) The internal energy of the small system is minimized. (c) The total entropy of the reservoir plus small system is maximized.

(a) Conservation of energy requires this probability distribution. (b) We need to take into account the degeneracy at each value of E. (c) As the small system's energy increases, the entropy of the reservoir decreases.

(a) Δμ = 0 J (b) Δμ = 2.87 × 10^{-21} J (c) Δμ = -2.87 × 10^{-21} J (d) Δμ = 1729 J (e) Δμ = -1729 J

(a) μ_{AL} = μ_{BR} (b) F_{AL} = F_{BR} (c) μ_{AL} + μ_{AR} = μ_{BL} + μ_{BR} (d) F_{AL} +F_{BL} = F_{AR} + F_{BR} (e) μ_{AL} + μ_{BL} = μ_{AR} + μ_{BR}

At a temperature of 300 K, the density of electrons in the conduction band of a particular intrinsic semiconductor is n_{e} = 10^{10}. The energy gap in this semiconductor is 1.0 eV.

Suppose we dope the semiconductor so that n_{e} = 10^{9}. What is the density n_{h} of holes after we do this?

(a) n_{h} = 1.00 × 10^{9} / m^{3} (b) n_{h} = 3.16 × 10^{9} / m^{3} (c) n_{h} = 1.00 × 10^{10} / m^{3} (d) n_{h} = 3.16 × 10^{10} / m^{3} (e) n_{h} = 1.00 × 10^{11} / m^{3}

(a) n_{e} = 1.45 × 10^{9} / m^{3} (b) n_{e} = 9.01 × 10^{9} / m^{3} (c) n_{e} = 1.10 × 10^{10} / m^{3} (d) n_{e} = 1.14 × 10^{10} / m^{3} (e) n_{e} = 4.82 × 10^{11} / m^{3}

(a) P = 1 × 10^{-18} W (b) P = 2 × 10^{-17} W (c) P = 4 × 10^{-16} W (d) P = 1 × 10^{- 3} W (e) P = 1000 W

(a) f = 2.1 × 10^{12} Hz (b) f = 3.2 × 10^{12} Hz (c) f = 5.3 × 10^{12} Hz (d) f = 2.1 × 10^{13} Hz (e) Cannot be determined.

Consider a collection of N nuclear spins, each with its associated magnetic moment μ. They are placed in the earth's magnetic field B, leading to the energy-level diagram shown here:

If the earth's magnetic field magnitude is 0.5 × 10^{-4} tesla (0.5 gauss), and the magnetic moment is μ = 1.4×10^{-26} J/T, what is the largest temperature that will allow the probability P_{ground} that a given spin will be in the lowest energy state to be 10%?

(a) T < 5 nK (b) T < 50 nK (c) T < 500 nK (d) This will not occur at any temperature. (e) Cannot be determined from the information given.

(a) S_{0} = N k (b) S_{0} = N k ln(2) (c) S_{0} = 2 N k

An exploratory satellite visiting a distant planet measures this pressure-versus-altitude plot. Assuming a gravitational acceleration of 1 m/s^{2}, and a uniform day-time temperature of 50 K, what single substance might we conclude makes up the atmosphere (at these altitudes)?

(a) H (b) H_{2} (c) He (d) N_{2} (e) Ar

(a) μ_{5km} > μ_{10km} (b) μ_{5km} = μ_{10km} (c) μ_{5km} < μ_{10km}

1. the gas is compressed under constant pressure to half its original volume 2. the gas is compressed under constant temperature to half its original volume 3. the gas is compressed to half its original volume without any heat added or removed

You observe that when a glass of water is left out on the kitchen counter, it is empty a few days later. Which one of the following explanations is incorrect?

(a) The fluctuations in the local temperature occasionally exceed the boiling temperature, thereby giving the molecules enough energy to become unbound. (b) The molecules are always leaving and rejoining the water in the glass, but the in-bound process is less likely. (c) The local partial pressure of water vapor just above the surface of the water is less than the vapor pressure of the water at room temperature.

(a) (b) (c) (d) (e)

(a) n(N_{2}O_{4}) / n(NO_{2}) will increase. (b) n(N_{2}O_{4}) / n(NO_{2}) will stay the same. (c) n(N_{2}O_{4}) / n(NO_{2}) will decrease.

A small amount of water (5 g) initially at 20°C is placed into a sealed container, with a movable piston. The air above the (massless) piston is at 1-atm pressure. Assume the heat of vaporization of water is 2260 kJ/kg and the specific heat of water is 4.2 kJ/kg-K.

Estimate the total change in entropy of the water as the temperature of the container is raised from 20°C to 100.01°C (i.e., just hot enough to boil the water). The three pictures represent the system as it is being heated but before boiling, while it is boiling, and after the boiling is completed.

(a) ΔS = 5.07 J/K (b) ΔS = 43.6 J/K (c) ΔS = 35.3 J/K (d) ΔS = 113 J/K (e) ΔS cannot be determined from the information given.

(a) No work is done, since both the pressure and temperature are constant. (b) 340 J (c) 860 J

(a) 5 (b) 50 (c) 150 (d) 250 (e) 500