Problem 1
In a \(1 \mathrm{~mm}^{3}\) volume, \(10^{15}\) atoms of argon are at a temperature of \(T=300 \mathrm{~K}\). Calculate the pressure of the gas.
Problem 2
Argon gas is enclosed in a container of a fixed volume. At \(T=300 \mathrm{~K}\), the pressure of the gas is \(50,000 \mathrm{~Pa}\). At \(T=350 \mathrm{~K},\) calculate the pressure of the gas.
Problem 4
A resistive heater is used to supply heat into an insulated box. The heater has current \(0.04 \mathrm{~A}\) and resistance \(1 \mathrm{k} \Omega,\) and it operates for one hour. Energy is either stored in the box or used to spin a shaft. If the box gains \(2,500 \mathrm{~J}\) of energy in that one hour, how much energy was used to turn the shaft?
Problem 5
Qualitatively, explain the difference between each pair of related quantities. (a) Seebeck effect and Peltier effect (b) Thermal conductivity and electrical conductivity
Problem 7
Explain how to measure each of the following quantities, and list the tools needed to make the measurement. (a) Electrical conductivity (b) Thermal conductivity (c) Peltier coefficient
Problem 9
A thermoelectric device is made from a material with resistivity 5 . \(10^{-8} \Omega \cdot \mathrm{m}\) and Seebeck coefficient \(8.5 \cdot 10^{-5} \frac{\mathrm{V}}{\mathrm{K}}\). A cube, \(1 \mathrm{~cm}\) on each side, was used to determine the thermal conductivity. One side of the cube was heated. At a steady state, the rate of energy transfer by conduction through the cube is \(1.8 \mathrm{~W}\). The temperature distribution through the material is linear, and a temperature difference across is measured to be \(20 \mathrm{~K}\) across the cube. Find the thermal conductivity \(\kappa,\) and find the figure of merit \(Z\) for the material.
Problem 11
A thermoelectric device is used to build a small refrigerator that can hold two pop cans. When the device is operating, the cold side of the device is at \(T=10{ }^{\circ} \mathrm{C}\) while the hot side of the device, outside the refrigerator, is at \(T=42^{\circ} \mathrm{C}\). What is the maximum possible efficiency of this device?
Problem 13
The Carnot efficiency describes the limit of the efficiency for some devices. Does it apply to the following types of devices? (Answer yes or no.) \- Hall effect device \- Semiconductor laser \- Photovoltaic device \- Piezoelectric device \- Pyroelectric device \- Thermoelectric device used as a temperature sensor \- Thermoelectric device used as a refrigerator \- Thermoelectric device used to generate electricity for a sensor system
