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Thermodynamics appeared 36 times across 3 years — 4.2% of Physics. This question is from Thermodynamic Processes.

Year 2026 2025 2024 Total
Questions 11 19 6 36

The pressure and volume of an ideal gas are related as PV3/2 = K (Constant). The work done when the gas is taken from state A (P₁, V₁, T₁) to state B (P₂, V₂, T₂) is:

Solution & Explanation

Related Formula

Work done in a polytropic process PV^x = constant:

W = (P₂V₂ - P₁V₁)/(1 - x)
Core Logic

Here, the polytropic exponent is x = (3)/(2). Substituting this exponent value into the generic polytropic work integral:

W = (P₂V₂ - P₁V₁)/(1 - (3)/(2)) = (P₂V₂ - P₁V₁)/(-(1)/(2))
Step 1: Simplify Sign Conventions
W = -2(P₂V₂ - P₁V₁) = 2(P₁V₁ - P₂V₂)

This represents the default standard convention for work executed by the gas medium.

Pattern Recognition

Polytropic model work formula is extremely useful. If x > 1, the denominator 1-x flips the index sequence from (2-1) to (1-2).

Chapter Mix

Class 11 Physics: Thermodynamics

Reference Study Guides

More Thermodynamics Previous-Year Questions — Page 8

Q jee_main_2024_31_jan_morning Isobaric Process
The given figure represents two isobaric processes for the same mass of an ideal gas, then
Isobaric Process diagram for Q38 - JEE Main 2024 Morning
A Volume vs Temperature (V-T) graph showing two straight lines starting from the origin representing distinct constant pressures P1 and P2.
  • A. P₂≥ P₁
  • B. P₂ > P₁
  • C. P₁ = P₂
  • D. P₁ > P₂

Solution

Related Formula

PV = nRT

Core Logic

From the Ideal Gas Law:

V = ((nR)/(P)) T

In a V-T graph, the equation of the line represents y = mx, where the slope m is:

Slope = (nR)/(P) Slope ∝ (1)/(P)

Thus, a higher slope corresponds to a lower pressure.

Step 2: Compare Slopes

From the given figure, the slope of line 2 is greater than the slope of line 1:

(Slope)₂ > (Slope)₁

Therefore, inversely: P₂ < P₁ or P₁ > P₂.

Pattern Recognition

In V-T graphs, steeper lines mean lower Pressure. In P-T graphs, steeper lines mean lower Volume. It's an inverse inverse slope relationship.

Chapter Mix

Class 11 Physics: Thermodynamics

More Thermodynamics Questions — jee_main_2024_01_february_morning

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JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%) | JEE Physics: Waves (+15.5%) | Electrostatics: Concentric Shells (-29.7%) | Modern Physics: Photoelectric Clones (+34.2%) | Mathematics: Definite Integrals (+18.1%) | Chemistry: Coordination Splitting (-11.4%)