The First Law of Thermodynamics, also known as the law of energy conservation, emphasizes that energy cannot be created or destroyed.

• The heat engine is a practical application of this law, where thermal energy is converted into mechanical energy and vice versa.
• A bicycle pump is another example. When vigorous pumping action is applied, it becomes heated. This is due to the work done on the gas inside, thereby increasing its internal energy.
• Human metabolism also exemplifies the First Law of Thermodynamics. The human body converts food into heat, work, and fat storage - all of which are forms of energy transfer.

Therefore, the correct answer is D), "All of the above," as all options provided showcase the First Law of Thermodynamics in action.

Work done in a thermodynamic process is integral to the change in volume.

• In an isochoric process, the volume remains constant, which means the change in volume (∆V) is zero.
• Because work is proportional to this change in volume, in an isochoric process, no work is done.

Hence, the correct answer is B, "Isochoric".

An adiabatic process is one where no heat exchange occurs with the surroundings.

• In the escape of air from a burst tyre and cloud formation, the changes happen so quickly that there's no time for heat exchange, making them adiabatic processes.
• Slow expansion, on the other hand, allows for the exchange of heat with its environment, disqualifying it as an adiabatic process.

Therefore, the correct answer is C, "Slow expansion".

When a constant temperature is used, a process is called isothermal.

• Isochoric processes occur at constant volume, an isobaric process occurs at a constant pressure, and an adiabatic process is when no heat exchange occurs.
• Among these, only the isothermal process assures a constant temperature.

Thus, the correct answer is A, "Isothermal process".

• The universal gas constant, also known as R, is a fundamental concept in thermodynamics.
• It is possible to express specific heats in terms of constant pressure and constant volume (Cp and Cv).
• The relationship is given as R = Cp - Cv.
• Thus, the correct answer is A, "The difference between Cp and Cv".

• For a diatomic gas, Cv is the specific heat at constant volume.
• Gamma (γ) is ratio of the specific heat at constant pressure (Cp) to Cv - γ = Cp/Cv.
• Given Cv = 5R/2, we can calculate γ using the relationship Cp - Cv = R.
• Thus, the correct answer is C, "7/5".

• The First Law of Thermodynamics states that the total energy of a system remains constant.
• In a bicycle pump, no heat transfer occurs (Q = 0), leaving W and ΔU to be considered.
• The equation becomes 0 = W + ΔU, which rearranges to -W = +ΔU.
• The negative W signifies work done on the system, while ΔU is the increase in internal energy.
• Hence, the correct answer is C, "-W = +ΔU".

• Thermodynamics involves various processes, including isothermal, isobaric, adiabatic, and isochoric.
• During an isochoric process, the volume of the system remains unchanged, which means that no work is done (W = 0).
• When applying the first law of thermodynamics (Q = ΔU + W), if W = 0, the equation simplifies to Q = ΔU.
• Consequently, the correct answer is D, "Isochoric process".

• Cp and Cv are specific heats at constant pressure and constant volume, respectively. For any gas, the difference between Cp and Cv equals the gas constant (R).
• As R is the same for both hydrogen and nitrogen, the difference for each gas is expressed as R/M, where M is the molar mass of the gas.
• For hydrogen, M = 2g, so 'a' = Cp - Cv = R/2. For nitrogen gas, M = 28g, making 'b' = Cp - Cv = R/28.
• Therefore, the correct relationship is a = 14b.

• For a monoatomic gas, Cv stands for the specific heat at constant volume.
• Gamma (γ) is defined as the ratio of the specific heat at constant pressure (Cp) to Cv, or γ = Cp/Cv.
• If we know Cv = 3R/2, we can calculate γ using the formula Cp - Cv = R.
• Thus, the correct answer is B, "5/3 or 1.67".

C = Q/nΔT

In thermodynamics, work done is contingent upon the type of process.

For an isochoric process, the volume remains constant, meaning no work is performed (ΔV=0, W=0).

Hence, B "Isochoric process" is the correct answer.

• An adiabatic process is a thermodynamic process in which there is no heat exchange (Q=0).
• The correct answer is thus A, "Heat transfer", as it remains constant in an adiabatic process.

• Thermodynamic state of a substance is determined by factors such as pressure, temperature, and volume.
• However, work is not a property of the system or surrounding, but a path variable.
• Thus, it does not characterize the state of matter, making A "Work" the correct answer.

• Substance with greater specific heat takes more time to heat up or cool down.
• If we draw a line parallel to the time axis, it intersects the provided graphs at three different points. The corresponding points on the time axis indicates that: tC > tB > tA, which implies CC > CB > CA.
• Therefore, the answer is C, "Substance C".

• The First Law of Thermodynamics primarily introduces the concept of internal energy and not entropy (which is related to the Second Law of Thermodynamics).
• Therefore, option A, "It introduces the concept of internal energy" is the correct answer.

• For any cyclic process, the initial and final states are the same, which means there won't be any change in internal energy (E = 0 or ΔU = 0).
• From the First Law of Thermodynamics, we get that Q = E + W, so Q = W ≠ 0.
• Therefore, the correct answer is C, "ΔU = 0". Note: The work done in a cyclic process equals the area under the cycle.

• The First Law of Thermodynamics is essentially an embodiment of the principle of energy conservation.
• It suggests that the heat supplied to a gas elevates its internal energy and allows it to work against expansion.
• Therefore, option B, "Energy conservation principle," is the correct answer.

• The difference between the two specific heats at constant pressure (CP) and constant volume (CV) for a given substance is equal to the universal gas constant (R).
• Therefore, option B, "Universal gas constant," is the correct answer.

• The temperature of a gas is determined by the kinetic energy of its molecules, not the potential energy or intermolecular forces.
• Therefore, the correct answer is B, "Kinetic energy of its molecules".

• In an isothermal process, the temperature is constant, which means ΔT = 0.
• Specific heat is calculated by the formula C = Q/mΔT. As ΔT = 0, this would make the specific heat Infinite.
• Therefore, option B, "Infinite," is the correct answer.

• In the case of an adiabatic process, there's no transfer of heat or matter, meaning Q = 0.
• Applying this condition to the formula of the First Law of Thermodynamics gives W = -ΔU.
• Therefore, option C, "W = -ΔU," is the correct answer.

• From the First Law of Thermodynamics, we know that Q = ΔU + W.
• For a process at constant temperature (isothermal), ΔU = 0.
• Substituting this into the equation gives Q = W.
• Therefore, the correct answer is C, "Q = W".

• The First Law of Thermodynamics primarily articulates that heat is a form of energy.
• It is subject to the conservation of energy principle, asserting that energy cannot be created or destroyed.
• Correspondingly, it can be considered a restatement of the Law of Conservation of Energy.
• Hence, option B, "Conservation of Energy Law" is the correct answer.

• When the volume of a gas is maintained constant throughout the heating process, it results in no volume change (∆V = 0).
• From the formula W = P∆V, substituting ∆V = 0, we get W = 0.
• Therefore, option C, "Zero," is the correct answer.

• The conversion of calories to joules is done using the relation 1 cal = 4.184 joules.
• Thus, 250 cal translates to 250 * 4.184 J, which equals 1046 J.
• Therefore, the correct answer is D, "1046 Joule".

• The specific heat at constant volume (Cv) for a monoatomic gas is 3R/2.
• According to Mayer's relation, Cp = Cv + R.
• Substituting the given value of Cv into this formula gives us Cp = 5R/2.
• The ratio of specific heats (γ) is given as Cp/Cv.
• So, γ = (5R/2)/(3R/2), which simplifies to 5/3.