TLDR;
This session introduces a new series for GATE 2023 aspirants, focusing on mastering key concepts through theoretical and numerical sessions. The speaker discusses the importance of thermodynamics, including its weightage, study strategies, reference books, and preparation tips for maximizing marks. The session also covers fundamental concepts such as the relationship between heat and work, units and dimensions, and graph theory, emphasizing their importance in understanding thermodynamics.
- Introduction to the "Mastering GATE Concepts" series for GATE 2023.
- Discussion of thermodynamics: weightage, study tips, and reference books.
- Emphasis on understanding units and dimensions, and graph theory.
Introduction to the Session [0:00]
The session marks the beginning of a new series aimed at GATE 2023 aspirants, designed to help master key concepts through a combination of theoretical and numerical approaches. The speaker emphasizes the necessity of understanding concepts to solve numerical problems effectively, highlighting the interconnectedness of conceptual knowledge and practical application in scoring well on the exam. The session will cover thermodynamics, both basic and applied, with a detailed study plan to be revealed.
About the Speaker [2:46]
The speaker introduces himself as a mechanical engineering graduate from IIT Delhi and an Engineering Services Examination qualifier with experience in SAIL and a private consulting firm. He has been teaching and guiding students for competitive exams for over nine years and invites students to join his Telegram group, "Mechanical by Chandra Shekhar Sir," for doubt discussions. He encourages viewers to subscribe to the GATE Hindi and English YouTube channels for free content and guidance.
Announcement: Strategy for GATE 2023 [4:24]
Abhinav Negi will host a live session on March 13th, offering a complete strategy for cracking the GATE 2023 examination. This session is particularly important for second and third-year engineering students planning to prepare for GATE, as it will focus on developing the right strategy to convert study efforts into successful results. The speaker underscores the importance of proper guidance and strategy in competitive exam preparation.
Thermodynamics Schedule [5:51]
The speaker outlines the schedule for the thermodynamics series, including general introductions, theory sessions, and numerical practice sessions. The schedule includes dedicated sessions for basic concepts, the first and second laws of thermodynamics, entropy, and applied thermodynamics, culminating in a menti war covering the entire thermal engineering syllabus. Preparation time is allocated between theory and practice sessions to allow for thorough understanding and concept reinforcement.
Reference Books for GATE 2023 [7:35]
The speaker recommends Yunus Cengel and PK Nag for basic thermodynamics, noting that while the Engineering Services Examination (ESE) requires a broader syllabus including RAC, power plant, and IC engines, GATE focuses on thermodynamics and its applications. He advises GATE aspirants not to spend time studying RAC, power plant, or IC engines from separate books, but rather to focus on working cycles covered in thermodynamics books. Handwritten notes are emphasized as the best resource for revision. For ESE, specific books like CP Arora for RAC, ML Mathur and RP Sharma for IC engines, and Ganeshan or Khajuria and Dubey for power plant are suggested.
Connection Between Thermodynamics, Heat Transfer, and Fluid Mechanics [12:27]
The speaker highlights the close relationship between thermodynamics, heat transfer, and fluid mechanics, noting that GATE often includes questions combining concepts from multiple subjects. He recommends Yunus Cengel's books for all three subjects to better understand the connections between them. The way of presentation can vary across books, but the content remains consistent.
Syllabus Overview [14:43]
The speaker provides an overview of the thermodynamics syllabus, dividing it into basic and applied sections. Basic thermodynamics includes concepts like the zeroth law, energy interaction, first and second laws, entropy, and pure substances. Applied thermodynamics covers RAC, power plant, and IC engines. Understanding the basics is crucial for solving application-based questions, making it a prerequisite for mastering the subject.
Weightage of Thermodynamics in GATE [15:39]
The speaker discusses the weightage of thermal engineering, including basic and applied thermodynamics, in the GATE exam, noting it carries a significant 10-15% weightage. He emphasizes that thermodynamics is a simple, easy-to-understand, and high-scoring subject if prepared with the right strategy. The weightage of thermodynamics has been increasing, reflecting its importance as a basic subject in mechanical engineering.
Marks Weightage in GATE 2021 and 2022 [17:27]
The speaker presents the marks distribution for thermodynamics in GATE 2021 and 2022. In 2021, the questions from thermodynamics were for 11 marks in the first slot and 13 marks in the second slot. The questions were asked from basic thermodynamics, the first law, properties of pure substances, thermodynamic relationships, RAC, power plant cycles, and IC engine cycles. In 2022, the thermodynamics and applications contained 20 marks. The topics that were repeated are the first law, the second law, entropy, and applications of thermodynamics.
Thermodynamics: The Science of Energy [20:07]
Thermodynamics is defined as the science of energy transfer, focusing on the analysis of energy in motion and its effects on system properties. The speaker describes thermodynamics as the battle between heat and work, highlighting the differences between them. Heat is a disorganized, non-useful, low-grade energy form, while work is organized, useful, and high-grade. The concept of thermodynamics revolves around converting heat into work and vice versa.
Importance of Units and Dimensions [22:22]
The speaker emphasizes the importance of understanding units and dimensions in mechanical engineering. He poses a question about what a weighing machine reads, clarifying that it measures weight (in Newtons) rather than mass (in kilograms). He reviews fundamental dimensions and their SI units, stressing the ability to convert between units.
Ideal Gas Equation and Gas Constants [25:18]
The speaker discusses the ideal gas equation (PV = mRT) and differentiates between the specific gas constant (R) and the universal gas constant (R-bar). R-bar is 8.314 J/mol·K, while R is the specific gas constant with units of J/kg·K. He explains the relationship between R and R-bar (R = R-bar / molecular weight) and asks about the unit of molecular weight, emphasizing that it is gram per mole or kilogram per kilo mole.
Ideal Gas Law and Molecular Weight [27:48]
The ideal gas law is derived from Boyle's law, Charles's law, and Avogadro's law. The speaker asks for the molecular weight of hydrogen, which is 2 gram/mole or 2/1000 kg/mole. He emphasizes the importance of understanding units to avoid mistakes in calculations.
Graph Theory in Thermodynamics [29:36]
The speaker introduces the importance of graph theory in understanding thermodynamics, asking which has a steeper slope on a T-S diagram: an isobaric or an isochoric process. He explains basic graph theory concepts, including slope (dy/dx or tan theta), constant slope, and the relationship between slope magnitude and sign.
Slope and Curve Analysis [32:57]
The speaker discusses how to determine if the magnitude of a slope is increasing or decreasing based on a curve between y and x. He explains that if x increases and y decreases, the slope has a negative sign. If the curve is initially flat and becomes steep, the slope is increasing in magnitude.
Application of Graph Theory to Thermodynamic Processes [34:51]
The speaker applies graph theory to thermodynamic processes, discussing the slope of constant volume and constant pressure lines on a T-S diagram. He notes that the slope is positive and increasing for a constant volume process. He then asks about the slope of a P-V curve, comparing isothermal and adiabatic processes, and concludes that the adiabatic process has a steeper slope.
Conclusion and Preparation for Next Session [37:56]
The speaker concludes by emphasizing the importance of understanding units, dimensions, and graph theory for studying thermodynamics. He advises viewers to revise these concepts before the next session, which will cover basic concepts and the first law of thermodynamics. The next session is scheduled for Wednesday at 8:00 PM.
