Thermodynamics JEE Main Questions 2025: Important Practice Questions with PYQs
Candidates can practise Thermodynamics JEE Main Questions 2025 that have been provided here to ace the JEE Mains 2025 exam. Candidates can access solved problems, along with practice Thermodynamics JEE Main questions.
Thermodynamics JEE Main Questions 2025: What makes Thermodynamics different from other physics topics for JEE Mains 2025 is its very high potential for students to score marks in the JEE Mains 2025 exam. Often experts recommend candidates who are preparing for the JEE Main exam to practise Thermodynamics JEE Main Questions 2025 to successfully answer all the questions from this chapter. Moreover, solving as many questions from Thermodynamics for JEE Mains 2025 can help students to prepare well for the exams. Candidates can check this article on JEE Main 2025 Questions from Thermodynamics for more detailed knowledge.
Also Read: JEE Main Previous Year Question Paper
JEE Main 2025 Thermodynamics Important Questions - Formula Based
Candidates can check the questions along with their respective answers for the following sets of formula-based questions.
Q) A system absorbs 500 J of heat and does 200 J of work on the surroundings. What is the change in the internal energy of the system?
A) Δ U = Q - W
= 500 J - 200 J
= 300 J
Q) A 2 litre container holds an ideal gas at a pressure of 1 atm and a temperature of 300 K. If the temperature is increased to 600 K while keeping the volume constant, what will be the new pressure of the gas?
A) P1 / T1 = P2 / T2
P2 = P1 x T2 / T1
= 1 x 600 / 300
= 2 atm
Q) For an adiabatic process, if an ideal gas undergoes a change such that the initial pressure P1= 2 atm, volume V1 = 4L and the final volume V2 = 8L. Given γ = 1.4, find the final pressure P2?
A) P1V1γ = P2V2γ
2 × 41.4 = P2 x 81.4
P2 = 0.76 atm
Q) Calculate the work done by 1 mole of an ideal gas during an isothermal expansion at 300 K from an initial volume of 1 L to a final volume of 5 L
A) W = nRT ln (Vf / Vi)
= (1 mol) X (8.314 J/mol K) X (300K) ln (5/1)
= 1240 J
Q) Calculate the change in entropy when 1 mole of an ideal gas expands isothermally from a volume of 10 L to 20 L at 300 K.
A) ΔS = nR ln (Vf / Vi)
= (1 mol) X (8.314 J / mol K) ln (20 / 10)
= 5.76 J / K
Q) A Carnot engine operates between a hot reservoir at 500 K and a cold reservoir at 300 K. Calculate the efficiency of the Carnot engine.
A) η = 1 − Tc / Th
= 1 - 300 / 500
= 0.4 or 40%
Thermodynamics JEE Main Questions 2025 - Conceptual Questions
Candidates can check the questions along with their respective answers for the following sets of conceptual questions.
Q) Which of the following statements about an isothermal process is true?
A) The internal energy of the system remains constant.
B) The temperature of the system changes.
C) The work done by the system is zero.
D) The system does not exchange heat with the surroundings.
Answer : A
Q) Which law of thermodynamics states that the entropy of an isolated system always increases over time?
A) Zeroth Law
B) First Law
C) Second Law
D) Third Law
Answer : C
Q) For an ideal gas, which of the following expressions correctly describes the relationship between heat (Q), work (W), and change in internal energy (ΔU) in a cyclic process?
A) Q = W + ΔU
B) ΔU = W + Q
C) Q = ΔU
D) ΔU = 0
Answer : D
Q) The efficiency (η) of a heat engine is given by η = 1 - (T_c / T_h), where T_c is the temperature of the cold reservoir and T_h is the temperature of the hot reservoir. What type of process is this engine operating in?
A) Isothermal
B) Adiabatic
C) Isobaric
D) Isometric
Answer : A
Q) For an ideal gas undergoing an isothermal expansion, which of the following quantities remains constant?
A) Pressure
B) Volume
C) Temperature
D) Internal Energy
Answer : C
Q) In an adiabatic process, which of the following is true about the heat transfer?
A) Heat is absorbed by the system.
B) Heat is released by the system.
C) There is no heat transfer between the system and the surroundings.
D) The heat transfer is equal to the work done by the system.
Answer : C
Practise Questions for JEE Mains 2025
Candidates must solve the following practice questions for JEE Mains 2025.
Q 1) For an ideal gas undergoing an isobaric process, which of the following is true?
A) The pressure remains constant, and the volume changes.
B) The volume remains constant, and the temperature changes.
C) The temperature remains constant, and the pressure changes.
D) The internal energy remains constant.
Q 2) The change in enthalpy ΔH during a chemical reaction is equal to:
A) The heat absorbed or released at constant volume
B) The work done by the system
C) The heat absorbed or released at constant pressure
D) The change in internal energy minus the work done
Q 3) The first law of thermodynamics is a statement of the conservation of:
A) Energy
B) Momentum
C) Mass
D) Charge
Q 4) Which of the following statements is true for an isothermal process?
A) The temperature remains constant, and internal energy remains constant.
B) The temperature remains constant, and heat is transferred into or out of the system.
C) The volume remains constant, and work is done on or by the system.
D) The pressure remains constant, and the system is isolated.
Q 5) For an ideal gas, the internal energy depends only on:
A) Pressure
B) Volume
C) Temperature
D) Pressure and Volume
Q 6) The efficiency of a heat engine is given by
A) Heat Input / Work Output
B) Work Output / Heat Input
C) Heat Output / Heat Input
D) (Heat Input - Heat Output) / Heat Input
Answer Box | |||||
1) A | 2) C | 3) A | 4) B | 5) C | 6) B |
Related Reads
Candidates can check this article to solve Thermodynamics JEE Main Questions 2025 along with practising the conceptual and formula-based questions. Stay tuned to Collegedekho for the latest updates on JEE Mains 2025.
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How much time is required to prepare for the JEE Mains exam?
Although maximum candidates usually require one or two years to prepare for the JEE Main and the JEE Advanced exam, candidates can also ace these exams with a tight study routine of 6 months.
Is HC Verma enough for the JEE Mains physics preparation?
HC Verma is considered to be a good book for the JEE Main preparation. It comprises good explanations and many practice problems. However, it is not enough for the preparations and candidates are required to study the NCERT textbooks as well.
Is the JEE Mains physics paper easy?
The physics section in the JEE Main exam is typically of moderate level of difficulty. It comprises a mix of numerical and concept-based questions.
Is 75 marks compulsory in the JEE Mains exam?
Candidates must keep in mind that there is no requirement of 75% marks in class for appearing in the JEE Main exam. The JEE Main eligibility criteria of minimum 75% marks in class 12 is required at the time of admission in NITs, IIITs and GFTIs. Candidates can apply and appear in the JEE Main exam irrespective of their class 12 marks.
What are the questions asked in the JEE Main exam?
The JEE Main exam has a total of 90 questions from all three subjects. The JEE Main exam has 30 questions each from the subjects of Physics, Chemistry and Mathematics. Out of 30 questions, there are 20 multiple choice questions and 10 are questions with numerical value answers.
Is NCERT enough for the JEE Mains preparation?
The official syllabus of JEE Main entrance exam and NCERT books cover almost all topics, and it is preferred by the candidates for their preparation. The syllabus of JEE Main and that of CBSE's Class 11 and 12 board is almost the same. Candidates can consider NCERT books as one of the best reference materials for the JEE Main exam.
Can candidates get admission into NIT with 35,000 rank in the JEE Main exam?
Some NITs and IIITs which candidates can get with 35000 rank in the JEE Main entrance exam are Indian Institute of Information Technology Kalyani, National Institute of Technology Mizoram, Indian Institute of Information Technology Dharwad, National Institute of Technology Nagaland, and National Institute of Technology Manipur.
Is it easy to score 99 in the JEE Mains exam?
The exact marks to be obtained for getting the 99 percentile in the JEE Main exam depends on the difficulty level of the paper. If the JEE Main question paper turns out to be easy, then marks secured by most of the candidates are good and the higher percentile is relative and gets pushed for higher marks.
Is 40 considered to be a good score in the JEE Main exam?
No, 40 is regarded as a very good score in the JEE Main exam. Since 85 to 95 percentile is considered to be good for admission into NITs, and IITs, securing anything less than that is not a good score for the General, OBC, and EWS candidates. With this score, such candidates can barely make it through a few engineering colleges of India.