Thermodynamics: Tricky Questions Part 1

Thermodynamics: In simple words, Thermodynamics is a branch of Physics that deals with the transfer of energy from one place to another and from one form to another. Thermodynamics can also be viewed as the relationship that exists between heat, temperature, work and energy. In formal terms, it is the science of the relationship between heat and other forms of energy.  

Thermal energy is the energy generated from heat. So when we talk of Thermodynamics, we essentially talk of how thermal energy is converted from one form of energy to another. Furthermore, we also talk of how matter is affected by the conversion process. Let us look at some of tricky questions for thermodynamics.

Tricky Questions for Thermodynamics Part-1

Here are a few tricky questions from thermodynamics that students can solve: 

Q.1. We obtain Isothermal Curves by drawing: 

1. P versus V
2. PV versus R
3. P versus T
4. PV versus T 

Q.2. Out of the following parameters, which does not characterise the thermodynamic state of matter? 

1. Volume
2. Work
3. Pressure
4. Temperature 

Q.3. Why can’t even a Carnot heat engine give 100% efficiency? That’s because, we cannot: 

1. Eliminate friction 
2. Prevent radiation 
3. Find ideal sources 
4. Reach absolute zero temperature 

Q.4. Let’s heat 100 g of water from 30 °C to 50 °C. If we Ignore the slight expansion of the water, the change in its internal energy is: 

(a) 4.2 kJ

(b) 8.4 kJ

(c) 84 kJ

(d) 2.1 kJ

Q.5. 0.048 eV is the average translational kinetic energy of 02 (molar mass 32) molecules at a particular temperature. What would be the translational kinetic energy of N2 (molar mass 28) molecules in eV at the same temperature?

(a) 0.0015

(b) 0.003

(c) 0.048

(d) 0.768

These are a few tricky questions that would make students rack their brains. By answering such questions, students would be in a better position as they face their exams. 

Laws of Thermodynamics

As and when students study Thermodynamics in their preparation for JEE exams, it is imperative that they recap the Laws of Thermodynamics. Here are the four Laws of Thermodynamics: 

Zeroth law: If two systems are in thermal equilibrium with a third system, then all the three systems are in thermal equilibrium with one another. 

First law: Energy can neither be created nor destroyed, but only be transformed from one form to another. 

Second law: For any isolated system, the entropy always increases. 

Third law: The entropy of a system approaches a constant value as the temperature approaches absolute zero. 

Thermodynamics: Important Terms 

Here are a few important terms which a student should keep in mind as they study Thermodynamics: 

1. Heat: In simple terms, heat is the transfer of energy from one body to another as a result of difference in temperature. 
2. Temperature: In simple terms, it is the degree of heat present in a substance. 
3. Work: Energy transferred by a system to its surroundings. 
4. Energy: It is the ability to do work or bring about change. 
5. Object: Something that has defined boundaries and permeabilities. 
6. Surrounding: The space that surrounds an object. 
7. Universe: The system put together with its surroundings. 

Thermodynamics: Different Types of Processes 

Here’s a recap of the different types of process when a student studies Thermodynamics: 

1. Isothermal Process: A process in which the temperature remains constant throughout the process from the initial to the final state. 
2. Isobaric Process: A process in which the pressure remains constant throughout the process from the initial to the final state.
3. Isochoric Process: A process in which the volume of the system remains constant from the initial to the final state.
4. Adiabatic Process: A process in which there is no exchange of heat between the system and the surrounding from the initial to the final state.

Tips to Score Better in Thermodynamics Questions

Thermodynamics is an important chapter in JEE Mains. It carries a substantial weightage in terms of questions asked in the examinations. As many as three questions are asked from the chapter Heat and Thermodynamics in the JEE Mains, which carry combined marks of 12. So if a student is not adept in this chapter, the loss will be heavy.  

We provide a few tips so that the student can score high in the exams: 

1. Since it is about Thermodynamics, it is needless to say that the student must be thorough with all the laws of Thermodynamics. From the zeroth to the third law, the student must be in a position to understand them clearly so that they can apply it to the problems later. 
2. The student has to manage time effectively and efficiently. It is imperative that the student practice the concepts hard and revise them. Embibe has an excellent repository of teaching concepts related to thermodynamics on its learn module.
3. While solving problems, it is essential that the data given is extracted correctly and the problem understood meticulously. If the problem is understood currently, the data can be substituted in the equation and the solutions can be obtained easily. 
4. Students must take up mock tests. By solving more and more questions in mock tests, the student gets an opportunity to test themselves and gain more confidence. Embibe has an excellent test module which the student can make use of. 

The student can access the JEE Main Mock Test from Embibe. We hope this article on Thermodynamics helps the student in their preparation for JEE. To get access to a world of study materials which enable a student to prepare themselves assiduously for many competitive exams, keep do visiting Embibe.