Question 1

A blackbody at temperature $T$ emits radiation energy per unit area per unit time according to the Stefan-Boltzmann law. If the temperature of the blackbody is doubled, by what factor does the radiation energy increase?

Accepted Answer

Correct Option: D. Solution: According to the Stefan-Boltzmann law, the radiation energy emitted per unit area per unit time is proportional to $T^4$. If the temperature is doubled, the radiation energy increases by a factor of $2^4 = 16$.

Question 2

Which of the following statements about calorimetry is true?

Accepted Answer

Correct Option: A. Solution: Calorimetry is the science of measuring the heat of chemical reactions or physical changes as well as heat capacity.

Question 3

Which of the following statements correctly describes the concept of specific heat capacity?

Accepted Answer

Correct Option: A. Solution: Specific heat capacity is defined as the amount of heat required to change the temperature of a unit mass of a substance by one degree, typically expressed in J/kg·K.

Question 4

A sample of gas is initially at a temperature of 273 K and a pressure of 1 atm. If the gas is heated to 546 K while the volume is kept constant, what will the final pressure be?

Accepted Answer

Correct Option: B. Solution: According to Gay-Lussac's Law, which is part of the ideal-gas equation, $P/T = 	ext{constant}$ at constant volume. If the temperature is doubled from 273 K to 546 K, the pressure also doubles, resulting in a final pressure of 2 atm.

Question 5

What is the latent heat of vaporization for water at standard atmospheric pressure?

Accepted Answer

Correct Option: C. Solution: The latent heat of vaporization for water at standard atmospheric pressure is $22.6 	imes 10^5 	ext{ J kg}^{-1}$.

Question 6

Calculate the heat required to convert 2 kg of ice at $-10^{\circ}C$ to steam at $100^{\circ}C$. (Specific heat capacity of ice = $2100 	ext{ J kg}^{-1} 	ext{ K}^{-1}$, specific heat capacity of water = $4.18 	imes 10^3 	ext{ J kg}^{-1} 	ext{ K}^{-1}$, latent heat of fusion of ice = $3.35 	imes 10^5 	ext{ J kg}^{-1}$, latent heat of vaporization of water = $2.256 	imes 10^6 	ext{ J kg}^{-1}$)

Accepted Answer

Correct Option: C. Solution: The total heat required is the sum of heat to raise temperature of ice to $0^{\circ}C$, melt the ice, raise temperature of water to $100^{\circ}C$, and convert water to steam: $Q = m_{ice} s_{ice} \Delta T + m_{ice} L_f + m_{water} s_{water} \Delta T + m_{water} L_v = 7.02 	imes 10^6 	ext{ J}$.

Question 7

A 1 kg block of ice at 0°C is melted to form water at 0°C. If the latent heat of fusion of ice is $3.33 	imes 10^5 	ext{ J/kg}$, how much heat is required for this process?

Accepted Answer

Correct Option: B. Solution: The heat required to melt 1 kg of ice at 0°C is given by the formula $Q = mL$, where $m$ is the mass and $L$ is the latent heat of fusion. Substituting the values, $Q = 1 	imes 3.33 	imes 10^5 = 3.33 	imes 10^5 	ext{ J}$.

Question 8

If a steel rod is prevented from expanding by fixing its ends rigidly, what type of stress is developed in the rod?

Accepted Answer

Correct Option: B. Solution: When a steel rod is prevented from expanding by fixing its ends, compressive stress is developed due to the external forces provided by the rigid support.

Question 9

Which of the following statements about the ideal-gas equation is true?

Accepted Answer

Correct Option: B. Solution: The ideal-gas equation $$PV = \mu RT$$ combines Boyle's law and Charles' law to describe the behavior of gases.

Question 10

What is the triple point of water in terms of temperature and pressure?

Accepted Answer

Correct Option: B. Solution: The triple point of water is at 273.16 K and 0.006 atm, where solid, liquid, and vapor phases coexist.

Question 11

Which of the following statements is true about blackbody radiation?

Accepted Answer

Correct Option: C. Solution: Blackbody radiation has a continuous spectrum, and the peak wavelength of the emitted radiation shifts according to the temperature, as described by Wien's Displacement Law.

Question 12

In an isolated system, what is the principle of heat exchange?

Accepted Answer

Correct Option: B. Solution: In an isolated system, the heat lost by the hot body is equal to the heat gained by the cold body.

Question 13

What is the relationship between the coefficient of volume expansion ($\alpha_V$) and the coefficient of linear expansion ($\alpha_1$) for a material?

Accepted Answer

Correct Option: C. Solution: The coefficient of volume expansion ($\alpha_V$) is three times the coefficient of linear expansion ($\alpha_1$), i.e., $\alpha_V = 3\alpha_1$.

Question 14

Consider a blackbody at a temperature $T$. According to Wien's Displacement Law, what happens to the peak wavelength of the emitted radiation as the temperature of the blackbody increases?

Accepted Answer

Correct Option: B. Solution: According to Wien's Displacement Law, the peak wavelength of radiation emitted by a blackbody is inversely proportional to its temperature. As the temperature increases, the peak wavelength decreases.

Question 15

A 1.0 mol sample of an ideal gas is initially at a pressure of 2 atm and a temperature of 300 K. The gas undergoes an isothermal expansion until its volume doubles. What is the final pressure of the gas?

Accepted Answer

Correct Option: A. Solution: According to the ideal-gas equation $PV = \mu RT$, for an isothermal process (constant temperature), the product of pressure and volume remains constant. Initially, $P_1V_1 = P_2V_2$. Given that the volume doubles, $V_2 = 2V_1$. Therefore, $P_1V_1 = P_2(2V_1)$, which simplifies to $P_2 = \frac{P_1}{2} = 1 	ext{ atm}$.

Question 16

A thermos flask is designed to minimize heat transfer. Which of the following features of a thermos flask helps in reducing heat loss by conduction?

Accepted Answer

Correct Option: A. Solution: The vacuum between the double walls of a thermos flask minimizes heat transfer by conduction and convection, as there is no medium for these processes to occur.

Question 17

A gas is kept in a container at a constant temperature. If the pressure of the gas is increased by a factor of 2, what happens to the volume of the gas according to the ideal-gas equation?

Accepted Answer

Correct Option: C. Solution: According to Boyle's Law, which is part of the ideal-gas equation, at constant temperature, the pressure of a gas is inversely proportional to its volume ($PV = 	ext{constant}$). Therefore, if the pressure is doubled, the volume is halved.

Question 18

A 3 kg block of ice at -12°C is to be converted to steam at 100°C. Calculate the total heat required for this process. (Given: specific heat capacity of ice = $2100 \, 	ext{J} \, 	ext{kg}^{-1} \, 	ext{K}^{-1}$, specific heat capacity of water = $4186 \, 	ext{J} \, 	ext{kg}^{-1} \, 	ext{K}^{-1}$, latent heat of fusion of ice = $3.35 	imes 10^5 \, 	ext{J} \, 	ext{kg}^{-1}$, latent heat of vaporization of water = $2.256 	imes 10^6 \, 	ext{J} \, 	ext{kg}^{-1}$)

Accepted Answer

Correct Option: B. Solution: The total heat required is the sum of heat to raise the temperature of ice to 0°C, melt the ice, raise the temperature of water to 100°C, and convert water to steam. Total heat = $9.1 	imes 10^6 \, 	ext{J}$.

Question 19

Which of the following statements best describes latent heat?

Accepted Answer

Correct Option: A. Solution: Latent heat is defined as the heat absorbed or released during a phase change of a substance, such as melting or boiling, without changing its temperature.

Question 20

According to Wien's Displacement Law, what happens to the wavelength at which the energy emitted by a blackbody is maximum as the temperature increases?

Accepted Answer

Correct Option: B. Solution: Wien's Displacement Law states that the wavelength at which the energy emitted by a blackbody is maximum decreases with increasing temperature, given by $\lambda_m T = 	ext{constant}$.

Question 21

A cup of hot tea is placed on a table in a room with an ambient temperature of $25\degree C$. According to Newton's Law of Cooling, which of the following scenarios will result in the fastest cooling of the tea?

Accepted Answer

Correct Option: B. Solution: According to Newton's Law of Cooling, the rate of cooling is faster when the temperature difference between the body and the surroundings is greater. Lowering the room temperature increases this difference, resulting in faster cooling.

Question 22

Consider a steel rod and a copper rod of equal length and cross-sectional area, joined end to end. If the thermal conductivities of steel and copper are $K_s = 50 	ext{ W/mK}$ and $K_c = 385 	ext{ W/mK}$ respectively, and the ends are maintained at $100 \degree C$ and $0 \degree C$, what is the temperature at the junction?

Accepted Answer

Correct Option: B. Solution: Using the formula for heat transfer and equating the heat currents, $\frac{K_s 	imes A 	imes (100 - T_j)}{L} = \frac{K_c 	imes A 	imes (T_j - 0)}{L}$. Solving gives $T_j = 40 \degree C$.

Question 23

In a laboratory experiment, a rod of length $L = 1 	ext{ m}$ and cross-sectional area $A = 0.01 	ext{ m}^2$ is used to measure thermal conductivity. If the temperatures at the ends are $T_1 = 100 \degree C$ and $T_2 = 0 \degree C$ and the heat current is measured to be $H = 10 	ext{ W}$, what is the thermal conductivity $K$ of the rod?

Accepted Answer

Correct Option: B. Solution: Using the formula $H = \frac{KA(T_1 - T_2)}{L}$, rearrange to find $K = \frac{HL}{A(T_1 - T_2)} = \frac{10 	imes 1}{0.01 	imes 100} = 20 	ext{ W/mK}$.

Question 24

In a calorimetry experiment, 200 g of water at $20^{\circ}C$ is mixed with 100 g of copper at $80^{\circ}C$. Assuming no heat is lost to the surroundings, what will be the final temperature of the mixture? (Specific heat capacity of water = $4.18 	imes 10^3 	ext{ J kg}^{-1} 	ext{ K}^{-1}$, specific heat capacity of copper = $0.386 	imes 10^3 	ext{ J kg}^{-1} 	ext{ K}^{-1}$)

Accepted Answer

Correct Option: A. Solution: Using the principle of heat exchange: $m_1 s_1 (T_f - T_1) = m_2 s_2 (T_2 - T_f)$. Solving for $T_f$ gives $24.5^{\circ}C$.

Question 25

According to the Stefan-Boltzmann law, what is the power radiated by a black body proportional to?

Accepted Answer

Correct Option: A. Solution: The Stefan-Boltzmann law states that the power radiated by a black body is proportional to the fourth power of its temperature, given by the formula $H = A\sigma T^4$, where $\sigma$ is the Stefan-Boltzmann constant.

Question 26

A thermometer is calibrated such that it reads 0°C at the ice point and 100°C at the steam point. What would be the reading on this thermometer if the temperature is 50°F?

Accepted Answer

Correct Option: A. Solution: Using the conversion formula $$t_C = \frac{5}{9}(t_F - 32)$$, for 50°F, the Celsius temperature is 10°C.

Question 27

Consider two identical blackbodies, one at temperature $300 \, K$ and the other at $600 \, K$. What is the ratio of the peak wavelength of radiation emitted by the first blackbody to that of the second blackbody?

Accepted Answer

Correct Option: B. Solution: According to Wien's Displacement Law, the peak wavelength $\lambda_{max}$ is inversely proportional to the temperature ($\lambda_{max} \propto 1/T$). Therefore, the ratio of the peak wavelengths is $600/300 = 2:1$.

Question 28

A gas is contained in a sealed container with a fixed volume. If the temperature of the gas is increased, what happens to the pressure?

Accepted Answer

Correct Option: C. Solution: According to the ideal-gas equation, when the volume is constant and temperature increases, the pressure increases.

Question 29

Consider a spherical body of radius $r$ and emissivity $e$ at temperature $T$. If the surrounding temperature is $T_s$, what is the net rate of heat loss due to radiation?

Accepted Answer

Correct Option: A. Solution: The net rate of heat loss due to radiation is given by the Stefan-Boltzmann law: $H = e \sigma A (T^4 - T_s^4)$, where $A = 4 \pi r^2$ is the surface area of the sphere.

Question 30

If the pressure of an ideal gas is doubled while keeping the temperature constant, what happens to the volume?

Accepted Answer

Correct Option: B. Solution: According to Boyle's law, which is part of the ideal-gas equation, if the pressure is doubled and temperature is constant, the volume is halved.

Question 31

Which of the following materials has the highest coefficient of linear expansion?

Accepted Answer

Correct Option: A. Solution: From Table 10.1, Aluminium has the highest coefficient of linear expansion at $2.5 	imes 10^{-5} 	ext{K}^{-1}$.

Question 32

In an experiment, water is heated from $20\degree C$ to $80\degree C$. If the specific heat capacity of water is $4186 	ext{ J kg}^{-1} 	ext{ K}^{-1}$ and the mass of water is $0.5 	ext{ kg}$, calculate the amount of heat required.

Accepted Answer

Correct Option: B. Solution: The heat required is calculated using $Q = mc\Delta T$, where $m = 0.5 	ext{ kg}$, $c = 4186 	ext{ J kg}^{-1} 	ext{ K}^{-1}$, and $\Delta T = 80 - 20 = 60 	ext{ K}$. Thus, $Q = 0.5 	imes 4186 	imes 60 = 125580 	ext{ J}$.

Question 33

What is the specific heat capacity of water in J/kg·K?

Accepted Answer

Correct Option: B. Solution: Water has a specific heat capacity of 4186.0 J/kg·K, which is higher than most other substances, making it an effective coolant.

Question 34

Which of the following statements correctly describes the process of sublimation?

Accepted Answer

Correct Option: C. Solution: Sublimation is the process where a substance transitions directly from the solid state to the vapor state without passing through the liquid state.

Question 35

Which of the following materials has the highest coefficient of linear expansion?

Accepted Answer

Correct Option: A. Solution: Aluminium has the highest coefficient of linear expansion among the given materials, with a value of $2.5 	imes 10^{-5} 	ext{K}^{-1}$.

Question 36

A blacksmith wants to fit an iron ring onto a wooden wheel. The diameter of the wheel is 5.243 m and the diameter of the ring is 5.231 m at $27^{\circ}	ext{C}$. To what temperature should the ring be heated to fit the wheel?

Accepted Answer

Correct Option: B. Solution: Using the formula for linear expansion, $L_{T_2} = L_{T_1} (1 + \alpha_1 \Delta T)$, where $\alpha_1$ is the coefficient of linear expansion, the required temperature is $218^{\circ}	ext{C}$.

Question 37

A black body is placed in a room at temperature $T_s$. If the temperature of the black body is $T$ and it radiates energy according to the Stefan-Boltzmann law, which expression correctly represents the net rate of heat loss by the black body?

Accepted Answer

Correct Option: A. Solution: The net rate of heat loss by a black body in a room at temperature $T_s$ is given by the expression $H = \sigma A (T^4 - T_s^4)$, where $\sigma$ is the Stefan-Boltzmann constant, $A$ is the area, and $T$ is the temperature of the black body.

Question 38

A balloon is filled with a gas at 27°C and 1 atm pressure. If the temperature is increased to 127°C at constant pressure, what will happen to the volume of the gas?

Accepted Answer

Correct Option: B. Solution: According to Charles' Law, which is part of the ideal-gas equation, at constant pressure, the volume of a gas is directly proportional to its absolute temperature ($V/T = 	ext{constant}$). Increasing the temperature from 27°C to 127°C will increase the volume.

Question 39

If a black body has a temperature of $T$ and is placed in an environment with temperature $T_s$, which formula represents the net rate of radiant energy loss according to the Stefan-Boltzmann law?

Accepted Answer

Correct Option: A. Solution: The net rate of radiant energy loss for a body at temperature $T$ in surroundings at temperature $T_s$ is given by $H = \sigma A (T^4 - T_s^4)$, where $\sigma$ is the Stefan-Boltzmann constant and $A$ is the area.

Question 40

A composite rod is made of two materials, $A$ and $B$, with lengths $L_A = 10 	ext{ cm}$ and $L_B = 15 	ext{ cm}$, and thermal conductivities $K_A = 200 	ext{ W/mK}$ and $K_B = 100 	ext{ W/mK}$, respectively. If the temperature at the junction is $T_J = 50 \degree C$ and the ends are maintained at $T_A = 100 \degree C$ and $T_B = 0 \degree C$, what is the heat current through the rod?

Accepted Answer

Correct Option: A. Solution: Using the formula for heat current $H = \frac{KA(T_1-T_2)}{L}$, calculate for each section and equate for steady state: $\frac{200 	imes A 	imes (100 - 50)}{10} = \frac{100 	imes A 	imes (50 - 0)}{15}$. Solving gives $H = 100 	ext{ W}$.

Question 41

A calorimeter contains 0.3 kg of water at $50^{\circ}C$. A piece of ice at $0^{\circ}C$ is added to it. If the final temperature of the mixture is $6.7^{\circ}C$, what is the mass of the ice added? (Latent heat of fusion of ice = $3.33 	imes 10^5 	ext{ J kg}^{-1}$, specific heat capacity of water = $4.18 	imes 10^3 	ext{ J kg}^{-1} 	ext{ K}^{-1}$)

Accepted Answer

Correct Option: C. Solution: Using the principle of heat exchange, $m_{ice} L_f + m_{ice} s_{water} (T_f - 0) = m_{water} s_{water} (T_{initial} - T_f)$. Solving gives $m_{ice} = 0.15 	ext{ kg}$.

Question 42

A tungsten lamp has an emissivity of 0.4 and a surface area of $0.3 \, cm^2$. If the lamp is at a temperature of $3000 \, K$, calculate the power radiated by the lamp using the Stefan-Boltzmann constant $\sigma = 5.67 	imes 10^{-8} \, W \, m^{-2} \, K^{-4}$.

Accepted Answer

Correct Option: B. Solution: The power radiated by the lamp is given by $H = e\sigma A T^4$. Substituting the given values: $H = 0.4 	imes 5.67 	imes 10^{-8} 	imes 0.3 	imes 10^{-4} 	imes (3000)^4 = 60 \, W$.

Question 43

In a phase diagram, the point where all three phases of a substance coexist is known as the:

Accepted Answer

Correct Option: C. Solution: The triple point is the temperature and pressure at which the solid, liquid, and vapor phases of a substance coexist in equilibrium.

Question 44

A steel rod and a copper rod are joined end to end and placed between a furnace at $300^{\circ}	ext{C}$ and an ice box at $0^{\circ}	ext{C}$. If the length of the steel rod is 15 cm and the length of the copper rod is 10 cm, with thermal conductivities of $50.2 \, 	ext{J} \, 	ext{s}^{-1} 	ext{m}^{-1} 	ext{K}^{-1}$ and $385 \, 	ext{J} \, 	ext{s}^{-1} 	ext{m}^{-1} 	ext{K}^{-1}$ respectively, what is the temperature at the junction of the two rods?

Accepted Answer

Correct Option: A. Solution: Using the formula for thermal equilibrium, $T_0 = \frac{K_1 T_1 + K_2 T_2}{K_1 + K_2}$, where $K_1$ and $K_2$ are the thermal conductivities and $T_1$ and $T_2$ are the temperatures of the furnace and ice box respectively, the temperature at the junction is $44.4^{\circ}	ext{C}$.

Question 45

Consider a black body at temperature $T$ in a room with temperature $T_s$. If the emissivity of the black body is $e$, what is the expression for the rate of heat radiation from the black body?

Accepted Answer

Correct Option: C. Solution: The rate of heat radiation from a black body with emissivity $e$ is given by $H = e \sigma A (T^4 - T_s^4)$, where $\sigma$ is the Stefan-Boltzmann constant, $A$ is the area, and $T$ is the temperature of the black body.

Question 46

Which of the following equations represents the ideal-gas law?

Accepted Answer

Correct Option: A. Solution: The ideal-gas equation is given by $$PV = \mu RT$$, where $P$ is pressure, $V$ is volume, $\mu$ is the number of moles, $R$ is the universal gas constant, and $T$ is temperature.

Question 47

Which of the following statements about radiation is true?

Accepted Answer

Correct Option: B. Solution: Radiation is the transfer of energy through electromagnetic waves and does not require a medium, allowing it to transfer heat through a vacuum, such as the heat from the Sun reaching the Earth.

Question 48

If 3 kg of ice at -12°C is converted to steam at 100°C, which of the following steps requires the most heat energy?

Accepted Answer

Correct Option: D. Solution: Converting water at 100°C to steam at 100°C requires the most heat energy due to the high latent heat of vaporization.

Question 49

Why is steam at 100°C more dangerous than water at the same temperature?

Accepted Answer

Correct Option: B. Solution: Steam at 100°C carries more energy due to the latent heat of vaporization, which is $22.6 	imes 10^5 	ext{ J/kg}$, making it more dangerous than water at the same temperature.

Question 50

A copper rod and an iron rod are joined end to end. If the thermal conductivity of copper is greater than that of iron, which statement is true regarding the temperature gradient across the rods in a steady state?

Accepted Answer

Correct Option: B. Solution: In a steady state, the heat current is the same through both rods. Since the thermal conductivity of copper is greater, the temperature gradient must be greater in the iron rod to maintain the same heat current.

Question 51

How does the specific heat capacity of water compare to that of other common substances?

Accepted Answer

Correct Option: B. Solution: Water has a higher specific heat capacity compared to most metals, which means it requires more heat to change its temperature.

Question 52

What is the total heat required to convert 3 kg of ice at $-12^{\circ}	ext{C}$ to steam at $100^{\circ}	ext{C}$?

Accepted Answer

Correct Option: C. Solution: The total heat required is the sum of the heat to raise the temperature of ice to $0^{\circ}	ext{C}$, the heat to melt the ice, the heat to raise the temperature of water to $100^{\circ}	ext{C}$, and the heat to convert water to steam. This totals to $9.1 	imes 10^6 \, 	ext{J}$.

Question 53

A 0.15 kg aluminum sphere at 100°C is placed in a 0.14 kg copper calorimeter containing 0.25 kg of water at 20°C. If the final temperature is 23°C, what is the specific heat capacity of aluminum? (Specific heat capacity of water = 4186 J/kg·K, specific heat capacity of copper = 386 J/kg·K)

Accepted Answer

Correct Option: A. Solution: Using the principle of heat exchange, the heat lost by aluminum equals the heat gained by water and the calorimeter. Solving the equation gives the specific heat capacity of aluminum as 900 J/kg·K.

Question 54

An ideal gas is contained in a sealed, rigid container. If the temperature of the gas is increased from 300 K to 600 K, what happens to the pressure of the gas?

Accepted Answer

Correct Option: A. Solution: For a gas in a rigid container, the volume remains constant. According to the ideal-gas equation, $P/T = 	ext{constant}$ when volume is constant. Therefore, if the temperature doubles, the pressure also doubles.

Question 55

A metal rod is heated at one end and the heat is transferred to the other end. Which mechanism of heat transfer is primarily involved?

Accepted Answer

Correct Option: A. Solution: Conduction is the process of heat transfer through a material without any movement of the material itself. In the case of a metal rod, heat is transferred from the hot end to the cooler end through conduction.

Question 56

A substance is heated from solid to liquid and then to gas. During the phase change from solid to liquid, what happens to the temperature of the substance?

Accepted Answer

Correct Option: C. Solution: During the phase change from solid to liquid, the temperature of the substance remains constant as the heat supplied is used to overcome the latent heat of fusion.

Question 57

According to Newton's Law of Cooling, the rate of change of temperature of a body is proportional to which of the following?

Accepted Answer

Correct Option: A. Solution: Newton's Law of Cooling states that the rate of change of temperature of a body is proportional to the difference between its temperature and the ambient temperature.

Question 58

If 1 kg of ice at 0°C is converted to water at 0°C, how much heat is required?

Accepted Answer

Correct Option: A. Solution: The heat required to convert 1 kg of ice at 0°C to water at 0°C is the latent heat of fusion, which is $3.33 	imes 10^5 	ext{ J}$.

Question 59

Which factor does NOT affect the specific heat capacity of a substance?

Accepted Answer

Correct Option: D. Solution: The specific heat capacity depends on the nature and temperature of the substance, not its color.

Question 60

Which of the following is the correct expression for the heat current through a rod with thermal conductivity $K$, cross-sectional area $A$, and temperature difference $(T_1 - T_2)$ across its length $L$?

Accepted Answer

Correct Option: B. Solution: The correct expression for heat current is $H = \frac{KA(T_1 - T_2)}{L}$, where $K$ is the thermal conductivity, $A$ is the cross-sectional area, and $L$ is the length of the rod.

Question 61

What is the temperature at which the Celsius and Fahrenheit scales read the same value?

Accepted Answer

Correct Option: A. Solution: The Celsius and Fahrenheit scales read the same value at -40 degrees. This can be derived from the conversion formula between the two scales.

Question 62

Which of the following materials has the highest thermal conductivity based on the given data?

Accepted Answer

Correct Option: A. Solution: Silver has the highest thermal conductivity among the given options, with a value of 406 J K⁻¹.

Question 63

A metal rod is heated at one end while the other end is kept in contact with ice. Which mode of heat transfer is primarily responsible for the heat flow along the rod?

Accepted Answer

Correct Option: A. Solution: Conduction is the primary mode of heat transfer in solids where heat is transferred through direct contact between molecules.

Question 64

In a laboratory experiment, a gas is compressed from a volume of 4 L to 1 L at constant temperature. If the initial pressure was 1 atm, what is the final pressure of the gas?

Accepted Answer

Correct Option: C. Solution: According to Boyle's Law, $PV = 	ext{constant}$. If the volume is reduced to one-fourth, the pressure must increase by a factor of four to maintain the same product, so the final pressure is 4 atm.

Thermal Properties of Mat..

Learning Objectives

Learning Objectives

Revision Notes & Summary

Chapter Notes

Ideal-Gas Equation and Absolute Temperature

Thermal Expansion

Specific Heat Capacity

Latent Heat

Heat Transfer Mechanisms

Stefan-Boltzmann Law

Newton's Law of Cooling

Temperature, Heat and Temperature Scale

Calorimetry and Principle of Heat Exchange

Change of State and Phase Diagrams

Conduction and Thermal Conductivity

Thermal Radiation and Black Body Concepts

Exam Tips & Common Mistakes

Common Mistakes & Exam Tips

Ideal-Gas Equation and Absolute Temperature

Thermal Expansion

Specific Heat Capacity

Latent Heat

Heat Transfer Mechanisms

Stefan-Boltzmann Law

Newton's Law of Cooling

Temperature, Heat and Temperature Scale

Calorimetry and Principle of Heat Exchange

Change of State and Phase Diagrams

Conduction and Thermal Conductivity

Thermal Radiation and Black Body Concepts

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Practice Test – MCQs, True/False

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Multiple Choice Questions

Q1.A blackbody at temperature TTT emits radiation energy per unit area per unit time according to the Stefan-Boltzmann law. If the temperature of the blackbody is doubled, by what factor does the radiation energy increase?

Correct Answer: D

Q2.Which of the following statements about calorimetry is true?

Correct Answer: A

Q3.Which of the following statements correctly describes the concept of specific heat capacity?

Correct Answer: A

Q4.A sample of gas is initially at a temperature of 273 K and a pressure of 1 atm. If the gas is heated to 546 K while the volume is kept constant, what will the final pressure be?

Correct Answer: B

Q5.What is the latent heat of vaporization for water at standard atmospheric pressure?

Correct Answer: C

Correct Answer: C

Q7.A 1 kg block of ice at 0°C is melted to form water at 0°C. If the latent heat of fusion of ice is 3.33×105 J/kg3.33 \times 10^5 \text{ J/kg}3.33×105 J/kg, how much heat is required for this process?

Correct Answer: B

Q8.If a steel rod is prevented from expanding by fixing its ends rigidly, what type of stress is developed in the rod?

Correct Answer: B

Q9.Which of the following statements about the ideal-gas equation is true?

Correct Answer: B

Q10.What is the triple point of water in terms of temperature and pressure?

Correct Answer: B

Q11.Which of the following statements is true about blackbody radiation?

Correct Answer: C

Q12.In an isolated system, what is the principle of heat exchange?

Correct Answer: B

Q13.What is the relationship between the coefficient of volume expansion (αV\alpha_VαV​) and the coefficient of linear expansion (α1\alpha_1α1​) for a material?

Correct Answer: C

Q14.Consider a blackbody at a temperature TTT. According to Wien's Displacement Law, what happens to the peak wavelength of the emitted radiation as the temperature of the blackbody increases?

Correct Answer: B

Q15.A 1.0 mol sample of an ideal gas is initially at a pressure of 2 atm and a temperature of 300 K. The gas undergoes an isothermal expansion until its volume doubles. What is the final pressure of the gas?

Correct Answer: A

Q16.A thermos flask is designed to minimize heat transfer. Which of the following features of a thermos flask helps in reducing heat loss by conduction?

Correct Answer: A

Q17.A gas is kept in a container at a constant temperature. If the pressure of the gas is increased by a factor of 2, what happens to the volume of the gas according to the ideal-gas equation?

Correct Answer: C

Correct Answer: B

Q19.Which of the following statements best describes latent heat?

Correct Answer: A

Q20.According to Wien's Displacement Law, what happens to the wavelength at which the energy emitted by a blackbody is maximum as the temperature increases?

Correct Answer: B

Q21.A cup of hot tea is placed on a table in a room with an ambient temperature of 25°C25\degree C25°C. According to Newton's Law of Cooling, which of the following scenarios will result in the fastest cooling of the tea?

Correct Answer: B

Correct Answer: B

Correct Answer: B

Correct Answer: A

Q25.According to the Stefan-Boltzmann law, what is the power radiated by a black body proportional to?

Correct Answer: A