Relation between two principal specific heat of a gas : A gas has two specific heats What is the name of the following statement: “When two systems are in thermal equilibrium with a third system, then they are in thermal equilibrium with each other”? SHOW SOLUTION SHOW SOLUTION It has four fundamental laws. $\frac{1}{3} M c^{2}=R T$ ……. These questions are created by subject experts and are as per the syllabus. The molecules of ammonia continuously collide with one another. speed (c) of molecules of different gases shall be different. First law of thermodynamics. Differentiating on both sides, we get, The heat and thermodynamics chapter is very important as every year 2 to 3 questions can always be expected from this chapter. The gas performs of work to raise the lid, such that is has a final total energy of. $\left(\frac{d P}{d V}\right)_{A}=\gamma\left(-\frac{P}{V}\right)=\gamma\left(\frac{d P}{d V}\right)_{I}$ / Thermodynamics Multiple Choice Questions and Answers. If the number of molecules is increased to 2n. 120 seconds . Download India's Best Exam Preparation App. Year 11 Physics: Waves and Thermodynamics Practice. Then $N$ will be number of molecules present in volume $V$ i.e., $N$ will be Avogadro’s number. ... Related Questions. Why temperature beyond $1200^{\circ} \mathrm{C}$ cannot be measured accurately by a platinum resistance thermometer? Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. $\Rightarrow \frac{d P}{d V}=-\frac{P}{V}$ is slope of isothermal curve, Following are a Few Vital Thermodynamics MCQ … MCQ Questions for Class 11 Physics with Answers were prepared based on the latest exam pattern. State and explain first law of thermodynamics. R = Mr. Q. A great deal of effort, time, and money has been spent in the quest for the so-called perpetual-motion machine, which is defined as a hypothetical machine that operates or produces useful work indefinitely and/or a hypothetical machine that produces more work or energy than it consumes. Explain on the basis of kinetic theory : on pulling the piston out, the pressure of gas decreases. Then $N$ will be number of molecules present in volume $V$ i.e., $N$ will be Avogadro’s number. Thermodynamics touches on virtually every field of physics, from astrophysics to biophysics, because they all deal in some fashion with the change of energy in a system. Solution . An ideal gas is compressed at constant temperature, will its internal energy increase or decrease ? SHOW SOLUTION [CONFIRMED] JEE Main will be conducted 4 times from 2021! Yes, for example, in explosion of a bomb, chemical energy (which is a form of internal energy) is converted into kinetic energy. gas: A gas has two specific heats Explain the concept of temperature on the basis of kinetic theory? same. (ii) An explained above, there is no change in internal energy. 2) Why different types of sound are produced in different bikes, though they run on SI Engines? E. enthalpy, entropy, heat A contains a gas at standard temperature and pressure, B is completely evacuated. If $\Delta V$ is the change in volume at constant pressure, From first law, $\Delta Q=\Delta W+\Delta U$, $\Rightarrow \Delta Q=P \Delta V+\Delta U \quad \Rightarrow C_{P} \Delta T=P \Delta V+\Delta U$, $\Rightarrow P \Delta V+C_{V} \Delta T=C_{P} \Delta T[\text { From equation }(2)]$, $\Rightarrow\left(C_{P}-C_{V}\right) \Delta T=P \Delta V$ ………..(4), $\begin{array}{l}{\text { But from ideal gas equation, }} \\ {P V=R T \quad \text { ideal }} \\ {\text { From equation }(4), \text { we have, }}\end{array} \Rightarrow P \Delta V=R \Delta T$, $\left(C_{P}-C_{V}\right) \Delta T=R \Delta T$, (1) In above equation units of all quantities $\left(C_{P}, C_{V} \text { and } R\right)$ are Joule $m o l^{-1} K^{-1} .$ If $C_{P}$ and $d$ $C_{V}$ are expressed in units calorie $m o l^{-1} K^{-1},$ then $C_{P}-C_{V}=\frac{R}{J}$, (2) In above relation is expressed for one gram of gas, then, $C_{P}-C_{V}=\frac{r}{J}$. For its first half-billion years, Earth was lifeless. Atomic Structure Revision Video – Class 11, JEE, NEET. pressure will reduce to 0.5 atm. Buy Multiple Choice Questions On Space Science And Multiple Choice Questions Thermodynamics Physics Multiple Choice Questions On Space Science And Multiple Choi Explain why the efficiency of reversible engine is maximum ? (b) the gas is compressed or allowed to expand very quickly. $\therefore \Delta Q=1 \times C_{V} \times \Delta T=C_{V} \Delta T$ ……………(1), $\begin{array}{ll}{\text { As volume remains constant, }} \\ {d V=0} & {\therefore \Delta W=P \Delta V=0} \\ {\text { According to first law of thermodynamics, }} \\ {\Delta Q=\Delta U+\Delta W} \\ {\Rightarrow \Delta U=C_{V} \Delta T}\end{array}$. Further internal energy of an ideal gas depends on temperature only. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. 15.2: The First Law of Thermodynamics and Some Simple Processes. MCQs on Physics Thermodynamics : 1. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. It is possible to convert internal energy into work ? Physics problems: thermodynamics. eSaral provides you complete edge to prepare for Board and Competitive Exams like JEE, NEET, BITSAT, etc. Includes full solutions and score reporting. Although the root mean square speed of gas molecules is of the order of the speed of sound in that gas, yet on opening a bottle of ammonia in one corner of a room its smell takes time in reaching the other corner. Thus, the absolute zero is that temperature at which the r.m.s. Q. A gas is filled in a cylinder fitted with a piston at a definite temperature and pressure. At $T=0$ What will be the effect on the pressure of the gas? e . What does universal gas constant signifies. Q. Answers > Physics > Molecular Physics | Thermodynamics. There are four rules of thermodynamics, and these are: zero law states that if two systems are in thermal equilibrium with a third system, then the first two systems are in thermal equilibrium. What are the limitations of first law of thermodynamics ? Without the ability of a system to use energy within the system to do work — the heart of thermodynamics — there would be nothing for physicists to study. NEET Physics is the scoring paper in the medical entrance examination. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. These important questions from thermodynamics class 11 physics will play significant role in clearing concepts of Physics. Does the mass of body change when it is heated or cooled ? The LibreTexts libraries are Powered by MindTouch ® and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. $\left(\frac{d P}{d V}\right)=-\frac{P}{V}$ ………….. (1) internal energy of coffee will increase. Q. Conceptual Questions. NEET UG, JEE Main Physics Question Papers | Topic: Thermodynamics, Question Type: MCQs, Test: 01 8. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. Suppose a polyatomic gas molecule has n degrees of freedom. Q. (iv)No, since the process (called free expansion) is rapid and cannot be controlled. Q. Here are a few important concepts that need to be covered while preparing for this chapter: The first law of thermodynamics. (A) (P,c), (Q,d), (R,b), (S,a) 1 Answer. SHOW SOLUTION Is it against the second law thermodynamics ? (3) What is the nature of graph, taking $0^{\circ} \mathrm{C}$ along the $\mathrm{y}$ -axis and ‘F along the x-axis. Second law of thermodynamics. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. eSaral provides you complete edge to prepare for Board and Competitive Exams like JEE, NEET, BITSAT, etc. If three molecules have speed u1, u2, u3 what will be their average speed and r.m.s. (3) As value of molar gas constant $R$ is $(+v e) 8.31$ Jmol $^{-1} K^{-1}$, it implies that $C_{P}>C_{V}$ and their difference in equal to $8.31 J \mathrm{mol}^{-1} K^{-1}$. Which of the following laws is applicable for the behavior of a perfect gas SE; b. ES; c. ES. R Process – III (C) Isochoric. A carnot engine having an efficiency of 1 10 th of heat engine, is used as a refrigerator. Name the sink in case of steam engine ? (2) In above relation is expressed for one gram of gas, then, $C_{P}-C_{V}=\frac{r}{J}$ SHOW SOLUTION (c) has its internal energy changed? It is the temperature at which three phases of water namely ice, water and water vapour are equally stable and exist simultaneously. speed. Why does a gas get heated on compression ? If the number of molecules is increased to 2n. Isothermal process : That thermal process in which the pressure and volume of the system (gas) change but temperature remains constant is called isothermal process. What will be the effect on the pressure of the gas? If three molecules have speed u1, u2, u3 what will be their average speed and r.m.s. To help aspirants to score good marks in coming WBJEE 2018, the engineering section bring to you the notes of chapter Thermodynamics. Why can a ship not use the internal energy of sea water to operate its engine ? Since, can never be negative, therefore the value of absolute temperature T can never be negative. Is it against the second law thermodynamics ? In hot summer after a bath, the body’s. From eq. It is denoted by $C_{P}$. No, because internal energy of an ideal gas depends only on temperature of the gas. (a) if the gas in enclosed in a vessel whose walls are made of a highly insulating material and speed? Therefore pressure is halved i.e. $\begin{array}{ll}{\text { As volume remains constant, }} \\ {d V=0} & {\therefore \Delta W=P \Delta V=0} \\ {\text { According to first law of thermodynamics, }} \\ {\Delta Q=\Delta U+\Delta W} \\ {\Rightarrow \Delta U=C_{V} \Delta T}\end{array}$ Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. What is the ice-point on kelvin scale? The air will not be cooled, but will be heated because due to motion of the fan, the speed of air molecules will increase. Q. An electric refrigerator transfers heat from the cold cooling coils to the warm surroundings. $\Delta Q=1 \times C_{P} \times \Delta T \Rightarrow \Delta Q=C_{P} \Delta T$ …………. (a) No, heat has not been transferred to the coffee as the coffee is in thermos flask which is insulated from the surroundings i.e. Note (Assume room temperature is 20°C.) Q. $\overline{c^{2}} \propto T$ ………(v) Now, let 1 mole of same gas is given an amount of heat $\Delta Q$ at constant pressure so as to increase the temperature by $\Delta T,$ then, $\Delta Q=1 \times C_{P} \times \Delta T \Rightarrow \Delta Q=C_{P} \Delta T$ ………….(3). After a short time interval, the gas returns to equilibrium states which lies on its P-V-T surface. In this quiz, you will learn about these three laws. SHOW SOLUTION Q. SURVEY . We have transformed classroom in such a way that a student can study anytime anywhere. They move in all directions with different speeds. speed (c) of molecules of different gases shall be different. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. $P_{\gamma} v^{\gamma-1} . Here $\quad \Delta Q=\Delta W i . Therefore, $m N$will be gram molecular mass. This is the relation between $\gamma$ and. Since the speed of car is not increasing, the gravitational potential energy is converted into internal energy of the break drums which are heated. (i) What is the final pressure of the gas in A and B? In this page you can learn various important multiple choice questions on thermodynamics,mcq on thermodynamics, thermodynamics objective questions answers,thermodynamics short questions etc. (iii) What is the change in temperature of the gas? (A) First Law of Thermodynamics (B) Second Law of Thermodynamics These important questions from thermodynamics class 11 physics will play significant role in clearing concepts of Physics. SHOW SOLUTION Your email address will not be published. Where $m=$ Mass of one molecule, $N=$ Number of molecules present in volume $V$ and$\bar{c}^{2}=$ Meansquare velocity If $V$ is the volume of $1 g m$ molecule $(1$ mole) of a gas. How did life evolve from nonliving matter? What do you understand by triple point of water ? But if gas temperature T is less than $\mathrm{T}_{\mathrm{B}}$ then does it behaves like ideal gas. According to kinetic theory of gases, the pressure exerted by the gas is given by $P=\frac{1}{3} \frac{m N}{V} c^{2} \ldots \ldots$ (i) Q. $\Delta U=0$. How much heat energy was added to the system? What if you can't find your question in our library? Yes in heating or cooling, a body absorbs or loses energy. An ideal gas is compressed at constant temperature, will its internal energy increase or decrease ? In thermal contact, heat flows from a body at higher temperature to the body at lower temperature till temperatures become equal. 1. a. If not, why have feel cold ? (iv) Which single point is used as reference point in thermometer ? We have transformed classroom in such a way that a student can study anytime anywhere. Answer the following. The graph shows the variation of the product PV with respect to the pressure (P) of given masses of three gases A, B and C. The temperature is kept constant, state with proper arguments which of these gases is ideal. (ii) Specific heat at constant pressure $\left(\mathrm{C}_{P}\right):$ It is the amount of heat required to raise the temperature of unit mass of gas by $1^{\circ} \mathrm{C}$ at constant pressure. Monoatomic gas will have greater temperature rise because a monoatomic gas has only translational energy but diatomic gas has both translational as well as rotational energy. The entire system is thermally insulated. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. Accuracy: A team of editors takes feedback from our visitors to keep trivia as up to date and as accurate as possible. PART A. SHOW SOLUTION This is because external work is done by the compressor of this transfer of heat. Your physics homework can be a real challenge, and the due date can be really close — feel free to use our assistance and get the desired result. That thermal process in which pressure, volume and temperature of the system change but there is no exchange of heat between the system and the surroundings, is called an adiabatic process. But r.m.s. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. given by $\frac{d P}{d V}$. Students always get 1-2 questions … But from ideal gas equation, $P V=R T$ …..(iii) Mean kinetic energy is proportional to its absolute temperature. But as the different gases may have molecules of different masses, the r.m.s. There is a temperature known as Boyle’s temperature ( $\left.T_{\mathrm{B}}\right)$ for each real gas at which it behaves like an ideal gas. No, it is not against the second law. The second law of thermodynamics states that in every thermodynamics process, the variation of … A great deal of effort, time, and money has been spent in the quest for the so-called perpetual-motion machine, which is defined as a hypothetical machine that operates or produces useful work indefinitely and/or a hypothetical machine that produces more work or energy than it consumes. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. What is the source of mechanical energy so produced ? (iv) Do the intermediate state the system (before setting to final equilibrium state) be on its P-V-T surface ? Adiabatic process and What is the valve of work-done in a cyclic process ? The gas equation is, $P V^{\gamma}=$ constant, Slopes of isothermal and adiabatic curves, The slope of an isothermal or adiabatic curve is. The gas equation is, $P V^{\gamma}=$ constant, The molecules of a gas are 2n a state of continuous, rapid and random motion. $\Delta U=0$. Revision : Electricity. The energy required for doing work during isothermal expansion is acquired as heat by the gas from surroundings. Considering coffee as a system, (d) Now, as internal energy of system depends upon its temperature. Thermodynamics is a field of science that deals with the quantitative relationships between energy sources, and the study of heat and work interconversion. But from ideal gas equation, $P V=R T$ …..(iii). If $T=0$ then from eq. Refer the diagram and match the following. Beyond $1200^{\circ} \mathrm{C},$ platinum begins to evaporate. But as the different gases may have molecules of different masses, the r.m.s. Q. Hence they are not able to advance in one particular direction speedly. $\therefore \frac{d P}{d V}=-\frac{\gamma P V^{\gamma-1}}{V^{\gamma}}=-\frac{\gamma P}{V}$ Which of the following variables controls the physical properties of a perfect gas (a) pressure (b) temperature (c) volume (d) all of the above (e) atomic mass. PV diagrams - … First law of thermodynamics problem solving. Practice: Thermodynamics questions. d V+V^{\gamma} . (c) According to first law, $\Delta Q=\Delta U+\Delta W,$ however as here and negative, so be positive i.e. A gas does work during isothermal expansion ? ... Related Questions. Since, can never be negative, therefore the value of absolute temperature. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. This question bank is designed by expert faculties keeping NCERT in mind and the questions are updated with respect to upcoming Board exams. View all Physics important questions for all the chapters. Multiple choice questions: 1. (a) For an isothermal process, $P V=k$ (iii)As explained above, there is also no change in temperature. Questions on Thermodynamics, Physics – MCQs on Thermodynamics for NEET and JEE Main, Class 11 and Class 12 Multiple Choice Questions (MCQ I) Although the root mean square speed of gas molecules is of the order of the speed of sound in that gas, yet on opening a bottle of ammonia in one corner of a room its smell takes time in reaching the other corner. Thermodynamics is a branch of science which primarily focuses on the relations between heat and various other forms of energy, such as mechanical, chemical or electrical energy, and therefore the relationships between all forms of energy. According to this law, for any dynamical system in thermal equilibrium, the total energy is distributed equally amongst all the degrees of freedom and the energy associated with each molecule per degree of freedom is $\frac{1}{2} k T$, and hence a constant. SHOW SOLUTION Thus molecular motion ceases at zero kelvin. Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. Which single point is used as reference point in thermometer ? $y=m x-c,\left[c=\frac{5}{9}(F-32)\right]$, having slope $=5 / 9$. As a matter of fact, a total of 45 questions will be asked from Physics. Below are ten questions to test how well you know Waves and Thermodynamics for Year 11 Physics. Also Access CBSE Class 12 Physics Sample Papers Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. If the temperature of body increases by $1^{\circ} \mathrm{C},$ what will be change in temperature on kelvin scale? Thermodynamics is a branch of science which primarily focuses on the relations between heat and various other forms of energy, such as mechanical, chemical or electrical energy, and therefore the relationships between all forms of energy. The stop-cock is suddenly opened. SHOW SOLUTION We know kinetic energy of a molecule is proportional to the absolute temperature i.e. It is possible to convert internal energy into work ? speed. $\Rightarrow\left(C_{P}-C_{V}\right) \Delta T=P \Delta V$ ………..(4) $\Rightarrow \frac{1}{2} M c^{2}=\frac{3}{2} R T$ strategies to Crack Exam in limited time period. which is very easy to understand and improve your skill. Explain why the efficiency of reversible engine is maximum ? (i) Specific heat at constant volume $\left(C_{V}\right):$ It is the amount of heat required to raise the temperature of unit mass of a gas by $1^{\circ} C$ at constant volume. Why? Download eSaral App for Video Lectures, Complete Revision, Study Material and much more...Sol. As $\gamma$ is always greater than one, hence slope of adiabatic curve is greater than the slope of isothermal curve. Due to which the molecules of gas get more space to move about. Since glass contracts more than platinum, glass fixes on to the wire. Group: Science Science Quizzes : Topic: Physics In other words, an adiabatic curve is sleeper than an isothermal curve. Q. But $m N=M=$ Gram molecular mass Physics Question Thermodynamics? Q. This happens due to adiabatic expansion of air of the tube of the bicycle. October 18, 2019 by Rati S. Leave a Comment. Two cylinders A and B of equal capacity are connected to each other via a stop-cock. In physics, when we study thermodynamics, we say that we cannot find the work done in Irreversible processes, because in such processes, the different variables of gas are not defined. On the kinetic energy of the gas? With the help of AI we have made the learning Personalized, adaptive and accessible for each and every one. This question bank is designed by expert faculties keeping NCERT in mind and the questions are updated with respect to upcoming Board exams. (c) According to first law, $\Delta Q=\Delta U+\Delta W,$ however as here and negative, so be positive i.e. Q. (d) Now, as internal energy of system depends upon its temperature i.e. Q. Zeroth law of thermodynamics. (c) has its internal energy changed? View all Physics important questions for all the chapters. Some of the energy goes into changing the phase of the liquid to gas. and from eq. Q. Q. Relation between two principal specific heat of a gas : A gas has two specific heats, Relation between two principal specific heat of a, (i) Specific heat at constant volume $\left(C_{V}\right):$ It is the amount of heat required to raise the temperature of unit mass of a gas by $1^{\circ} C$ at constant volume. Now, let 1 mole of same gas is given an amount of heat $\Delta Q$ at constant pressure so as to increase the temperature by $\Delta T,$ then, Get important questions from Thermodynamics and Heat for Class 11 exams. Hence, temperature of gas will remain constant. Let 1 mole of a gas is supplied $\Delta Q$ amount of heat at constant volume so that the temperature of the gas rises by $\Delta T$. Q. 1.3. This is the reason due to which the lowest temperature on kelvin’s scale is assumed to be 0K. How is the mean kinetic energy of a gas related to its temperature? CBSE Class 11-Physics: Thermodynamics Problem's: Questions Doorsteptutor material for CBSE is prepared by world's top subject experts: fully solved questions with step-by-step explanation - practice your way to success.