Thermodynamic processes MCQ Quiz in मल्याळम - Objective Question with Answer for Thermodynamic processes - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക

CONCEPT:

• Isothermal process: When a thermodynamic system undergoes a physical change in such a way that its temperature remains constant, then the change is known as an isothermal process.
• Isobaric process: When a thermodynamic system undergoes a physical change in such a way that its pressure remains constant, then the change is known as the isobaric process.
• Isochoric process: When a thermodynamic process undergoes a physical change in such a way that its volume remains constant, then the change is known as the isochoric process.
• Adiabatic process: When a thermodynamic system undergoes a change in such a way that no exchange of heat takes place between Systems and surroundings, the process is known as an adiabatic process.

EXPLANATION:

First Law of Thermodynamics:

• It is a statement of conservation of energy in the thermodynamical process.
• According to it heat given to a system (ΔQ) is equal to the sum of the increase in its internal energy (ΔU) and the work done (ΔW) by the system against the surroundings.

i.e ΔQ = ΔU + ΔW          [∴ ΔW = p ΔV]​

• According to the question, the change in the internal energy of the system will be equal to work done on the system or by the system when the heat of the system remains constant. i.e., ΔQ = 0 

⇒ ΔU = - ΔW

CONCEPT:

• Isothermal process: When a thermodynamic system undergoes a physical change in such a way that its temperature remains constant, then the change is known as an isothermal process.
• Isobaric process: When a thermodynamic system undergoes a physical change in such a way that its pressure remains constant, then the change is known as the isobaric process.
• Isochoric process: When a thermodynamic process undergoes a physical change in such a way that its volume remains constant, then the change is known as the isochoric process.
• Adiabatic process: When a thermodynamic system undergoes a change in such a way that no exchange of heat takes place between Systems and surroundings, the process is known as an adiabatic process.

EXPLANATION:

• From above it is clear that, in isochoric processes, the volume remains constant. Therefore option 1 is correct.

Concept:

• Thermodynamics is the branch of science which deals with the study of energy transfers in a system or between the systems in the form of heat, work, and temperature. 
• There are four types of thermodynamic processes:

Isobaric process: The process in which pressure of the system remains constant is called as isobaric process.

Isochoric process: The process in which volume of the system remains constant is called as Isochoric process.

Isothermal process: The process in which temperature of the system remains constant is called as Isothermal process.

Adiabatic process: The process in which there is no exchange of heat between system and surroundings is called as Adiabatic process.

Explanation:

The curve and respective process represented by them is

1: Isochoric

2: Adiabatic

3: Isothermal

4: Isobaric

Hence option (3) is the correct answer.

The correct answer is option 3) i.e. on both the temperature and volume expansion ratio.

CONCEPT:

• An isothermal process is a thermodynamic process in which the temperature of a system remains constant.
  • Melting and evaporation are examples of the isothermal process.
  • The relation of pressure and volume of gas undergoing isothermal process is as shown.

• Work done in an isothermal process is given by

W = nRT ln(\(\frac{V_1}{V_0}\))

Where n is the number of molecules, R is the universal gas constant, T is the temperature, and V₁ and V₀ are the final and initial volume respectively.

EXPLANATION:

The work done in an isothermal process is given by:

W = nRT ln(\(\frac{V_1}{V_0}\)) ⇒ W ∝ T, ln(\(\frac{V_1}{V_0}\))

•  V1 and V0 are the final and initial volumes respectively, thus it represents the change in volume during expansion. 
• Therefore, work done in an isothermal change of a gas depends on both the temperature and volume expansion ratio.

CONCEPT:

First Law of Thermodynamics:

• It is a statement of conservation of energy in the thermodynamical process.
• According to it heat given to a system (ΔQ) is equal to the sum of the increase in its internal energy (ΔU) and the work done (ΔW) by the system against the surroundings.

i.e ΔQ = ΔU + ΔW          [∴ ΔW = p ΔV]

• It makes no distinction between work and heat as according to it the internal energy (and hence temperature) of a system may be increased either by adding heat to it or doing work on it or both.

EXPLANATION:

• When a thermodynamic system undergoes a physical change in such a way that its temperature remains constant, then the change is known as an isothermal process.
• As we know that, the internal energy of the system is a function of temperature alone, so in the isothermal process, the internal energy of the gas remains constant.

CONCEPT:

• Thermodynamic process: It is defined as a change from one equilibrium macrostate to another macrostate.

Different thermodynamic process:

EXPLANATION:

• From the above discussion, it's clear that option 1 is incorrect as in isochoric process volume is constant.
• The correct option is 1.

​Additional Information

• The initial and final states are the defining elements of the process.
• During such a process,  a system starts from the initial state i, described by a pressure pi, a volume Vi and a temperature Ti, passes through various quasi-static states to a final state f, described by a pressure pf, a volume Vf, and a temperature Tf. 
• In this process energy may be transferred from or into the system and also work can be done by or on the system. 

Diagram for the Processes:

CONCEPT:

• Boltzmann constant: It relates the average kinetic energy for each degree of freedom of a physical system in equilibrium to its temperature.

In an ideal gas in equilibrium at temperature T, the average kinetic energy per molecule is:

1/2 mv² = 3/2 kT 

where k is Boltzmann’s constant.

The value Boltzmann constant k is 1.38064852 × 10-23 m2 kg s-2 K-1.

EXPLANATION:

The value of Boltzmann constant k = 1.38064852 × 10-23 m2 kg s-2 K-1

So the correct answer is option 4.

The correct answer is option 3) i.e. Zero

CONCEPT:

• Cyclic process: It is a thermodynamic process where a system comes back to its initial state i.e. the system starts and returns to the same thermodynamic state.

• Internal Energy: The internal energy of a system is identified with the random, disordered motion of molecules;
  • The total (internal) energy in a system includes potential and kinetic energy.

The internal energy of an ideal gas is calculated by

U = nfRT/2

Change in internal energy is given by:

ΔU = nfRΔT/2

where n is the number of moles, f is the degree of freedom of gas, R is gas constant, and T is the temperature.

• Since the system return to the same state after each cycle, the change in internal energy is zero.
• In this case, the work done will be equal to the heat energy.

EXPLANATION:

• In a cyclic process (ΔT = 0 so ΔU = 0), the system remains the same after each cycle. Hence, the change in internal energy is zero.

CONCEPT:

EXPLANATION:

• In the Isobaric process, the pressure is constant. So option 3 is correct.

CONCEPT:

• First Law of Thermodynamics: This law state that if some amount of heat is supplied to the system which is capable of doing work, then the heat absorbed by the system will be equal to the sum of the increase in internal energy and work done by the system.

The first law of thermodynamics applied to an Isothermal Process is:

ΔQ = PΔV 

EXPLANATION:

The First Law of Thermodynamics is defined as:

ΔQ = ΔU + PΔV 

• Isothermal Process: The thermodynamics process occurs at a constant temperature, as the temperature remains constant in an isothermal process there will no change in Internal energy that is (ΔU = 0)  which can be written as: 

ΔQ = PΔV

• Hence, this is the valid formula of the First law of thermodynamics applied to an Isothermal Process.