PREVIOUS NEXT
1
JEE Main 2026 (Online) 28th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

$20.0 \mathrm{dm}^3$ of an ideal gas ' X ' at 600 K and 0.5 MPa undergoes isothermal reversible expansion until pressure of the gas is 0.2 MPa . Which of the following option is correct?

(Given: $\log 2=0.3010$ and $\log 5=0.6989$ )

A

$\mathrm{w}=-9.1 \mathrm{~kJ}, \Delta \mathrm{U}=0, \Delta \mathrm{H}=0, \mathrm{q}=9.1 \mathrm{~kJ}$

B

$\mathrm{w}=9.1 \mathrm{~J}, \Delta \mathrm{U}=9.1 \mathrm{~J}, \Delta \mathrm{H}=0 ; \mathrm{q}=0$

C

$\mathrm{w}=-3.9 \mathrm{~kJ}, \Delta \mathrm{U}=0, \Delta \mathrm{H}=0 ; \mathrm{q}=3.9 \mathrm{~kJ}$

D

$\mathrm{w}=+4.1 \mathrm{~kJ}, \Delta \mathrm{U}=0, \Delta \mathrm{H}=0 ; \mathrm{q}=-4.1 \mathrm{~kJ}$

2
JEE Main 2026 (Online) 24th January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The heat of atomisation of methane and ethane are ' x ' $\mathrm{kJ} \mathrm{mol}^{-1}$ and ' y ' $\mathrm{kJ} \mathrm{mol}^{-1}$ respectively. The longest wavelength ( $\lambda$ ) of light capable of breaking the $\mathrm{C}-\mathrm{C}$ bond can be expressed in SI unit as :

A

$\frac{\mathrm{N}_{\mathrm{A}} \mathrm{hc}}{250(y-6 x)}$

B

$\mathrm{N}_{\mathrm{A}} \mathrm{hc}\left(y-\frac{6 x}{4}\right)^{-1}$

C

$\frac{\mathrm{hc}}{1000}\left(\frac{y-6 x}{4}\right)^{-1}$

D

$\frac{\mathrm{N}_{\mathrm{A}} \mathrm{hc}}{250(4 y-6 x)}$

3
JEE Main 2026 (Online) 24th January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

$$ \text { Match the LIST-I with LIST-II } $$

List-I Isothermal process for ideal gas system List-II Work done ( 
<mi>V</mi>

<mi>f</mi>
> 
<mi>V</mi>

<mi>i</mi>


<mi>V</mi>

<mi>f</mi>
> 
<mi>V</mi>

<mi>i</mi>
V_(f) > V_(i) )
A. Reversible expansion I. 
<mi mathvariant="normal">w</mi>
= 0 
<mi mathvariant="normal">w</mi>
= 0 w=0
B. Free expansion II. 
<mi mathvariant="normal">w</mi>
= − 
<mi data-mjx-auto-op="false">nR</mi>
T ln ⁡ 
<msub>

  <mrow data-mjx-texclass="ORD">

    <mtext> </mtext>

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">f</mi>

    </mrow>

  </mrow>

</msub>

<msub>

  <mrow data-mjx-texclass="ORD">

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">i</mi>

    </mrow>

  </mrow>

</msub>


<mi mathvariant="normal">w</mi>
= − 
<mi data-mjx-auto-op="false">nR</mi>
T ln ⁡ 
<msub>

  <mrow data-mjx-texclass="ORD">

    <mtext></mtext>

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">f</mi>

    </mrow>

  </mrow>

</msub>

<msub>

  <mrow data-mjx-texclass="ORD">

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">i</mi>

    </mrow>

  </mrow>

</msub>
w=-nRT ln((V_(f))/(V_(i)))
C. Irreversible expansion III. 
<mi mathvariant="normal">w</mi>
= − 
<mrow data-mjx-texclass="ORD">

  <mi mathvariant="normal">p</mi>

</mrow>

<mrow data-mjx-texclass="ORD">

  <mrow data-mjx-texclass="ORD">

    <mi data-mjx-auto-op="false">ex</mi>

  </mrow>

</mrow>


<mo data-mjx-texclass="OPEN">(</mo>

<msub>

  <mrow data-mjx-texclass="ORD">

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">f</mi>

    </mrow>

  </mrow>

</msub>

<mo>−</mo>

<msub>

  <mrow data-mjx-texclass="ORD">

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">i</mi>

    </mrow>

  </mrow>

</msub>

<mo data-mjx-texclass="CLOSE">)</mo>


<mi mathvariant="normal">w</mi>
= − 
<mrow data-mjx-texclass="ORD">

  <mi mathvariant="normal">p</mi>

</mrow>

<mrow data-mjx-texclass="ORD">

  <mrow data-mjx-texclass="ORD">

    <mi data-mjx-auto-op="false">ex</mi>

  </mrow>

</mrow>


<mrow>

  <msub>

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">V</mi>

    </mrow>

    <mrow data-mjx-texclass="ORD">

      <mrow data-mjx-texclass="ORD">

        <mi mathvariant="normal">f</mi>

      </mrow>

    </mrow>

  </msub>  

  <mo>−</mo>  

  <msub>

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">V</mi>

    </mrow>

    <mrow data-mjx-texclass="ORD">

      <mrow data-mjx-texclass="ORD">

        <mi mathvariant="normal">i</mi>

      </mrow>

    </mrow>

  </msub>  

</mrow>
w=-p_(ex)(V_(f)-V_(i))
D. Irreversible compression IV. 
<mi mathvariant="normal">w</mi>
= − 
<mrow data-mjx-texclass="ORD">

  <mi mathvariant="normal">p</mi>

</mrow>

<mrow data-mjx-texclass="ORD">

  <mrow data-mjx-texclass="ORD">

    <mi data-mjx-auto-op="false">ex</mi>

  </mrow>

</mrow>


<mo data-mjx-texclass="OPEN">(</mo>

<msub>

  <mrow data-mjx-texclass="ORD">

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">i</mi>

    </mrow>

  </mrow>

</msub>

<mo>−</mo>

<msub>

  <mrow data-mjx-texclass="ORD">

    <mi mathvariant="normal">V</mi>

  </mrow>

  <mrow data-mjx-texclass="ORD">

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">f</mi>

    </mrow>

  </mrow>

</msub>

<mo data-mjx-texclass="CLOSE">)</mo>


<mi mathvariant="normal">w</mi>
= − 
<mrow data-mjx-texclass="ORD">

  <mi mathvariant="normal">p</mi>

</mrow>

<mrow data-mjx-texclass="ORD">

  <mrow data-mjx-texclass="ORD">

    <mi data-mjx-auto-op="false">ex</mi>

  </mrow>

</mrow>


<mrow>

  <msub>

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">V</mi>

    </mrow>

    <mrow data-mjx-texclass="ORD">

      <mrow data-mjx-texclass="ORD">

        <mi mathvariant="normal">i</mi>

      </mrow>

    </mrow>

  </msub>  

  <mo>−</mo>  

  <msub>

    <mrow data-mjx-texclass="ORD">

      <mi mathvariant="normal">V</mi>

    </mrow>

    <mrow data-mjx-texclass="ORD">

      <mrow data-mjx-texclass="ORD">

        <mi mathvariant="normal">f</mi>

      </mrow>

    </mrow>

  </msub>  

</mrow>
w=-p_(ex)(V_(i)-V_(f))

Choose the correct answer from the options given below:

A

A-IV, B-I, C-III, D-II

B

A-I, B-III, C-II, D-IV

C

A-II, B-I, C-III, D-IV

D

A-IV, B-II, C-III, D-I

4
JEE Main 2026 (Online) 23rd January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A cup of water at $5^{\circ} \mathrm{C}$ (system) is placed in a microwave oven and the oven is turned on for one minute during which the water begins to boil. Which of the following option is true?

A

$q=+v e, w=-v e, \Delta U=+v e$

B

$q=+v e, w=0, \Delta U=-v e$

C

$q=+v e, w=-v e, \Delta U=-v e$

D

$q=-v e, w=-v e, \Delta U=-v e$

PREVIOUS NEXT

JEE Main Subjects

Browse all chapters by subject

Physics
Mechanics
Units & Measurements Vector Algebra Motion in a Straight Line Motion in a Plane Circular Motion Laws of Motion Work Power & Energy Center of Mass and Collision Rotational Motion Properties of Matter Heat and Thermodynamics Simple Harmonic Motion Waves Gravitation
Electricity
Electrostatics Current Electricity Capacitor Magnetic Effect of Current Magnetic Properties of Matter Electromagnetic Induction Alternating Current Electromagnetic Waves
Optics
Wave Optics Geometrical Optics
Modern Physics
Atoms and Nuclei Dual Nature of Radiation Semiconductor Communication Systems
Chemistry
Physical Chemistry
Some Basic Concepts of Chemistry Structure of Atom Redox Reactions Gaseous State Chemical Equilibrium Ionic Equilibrium Solutions Thermodynamics Electrochemistry Chemical Kinetics and Nuclear Chemistry Solid State Surface Chemistry
Inorganic Chemistry
Periodic Table & Periodicity Chemical Bonding & Molecular Structure Isolation of Elements Hydrogen s-Block Elements p-Block Elements d and f Block Elements Coordination Compounds Salt Analysis Environmental Chemistry
Organic Chemistry
Basics of Organic Chemistry Hydrocarbons Haloalkanes and Haloarenes Alcohols, Phenols and Ethers Aldehydes, Ketones and Carboxylic Acids Compounds Containing Nitrogen Polymers Biomolecules Chemistry in Everyday Life Practical Organic Chemistry
Mathematics
Algebra
Sets and Relations Logarithm Quadratic Equation and Inequalities Sequences and Series Mathematical Induction Binomial Theorem Matrices and Determinants Permutations and Combinations Probability Vector Algebra 3D Geometry Complex Numbers Statistics Mathematical Reasoning
Trigonometry
Trigonometric Ratio and Identites Trigonometric Equations Inverse Trigonometric Functions Properties of Triangle Height and Distance
Coordinate Geometry
Straight Lines and Pair of Straight Lines Circle Parabola Ellipse Hyperbola
Calculus
Functions Limits, Continuity and Differentiability Differentiation Application of Derivatives Indefinite Integrals Definite Integration Area Under The Curves Differential Equations
EXAM MAP

Browse past year questions by exam & subject

Joint Entrance Examination
JEE Main JEE Advanced MHT CET BITSAT COMEDK WB JEE KCET VITEEE AP EAPCET TS EAMCET IAT (IISER)
Medical
NEET AIIMS MHT CET (Biology)
Graduate Aptitude Test in Engineering
GATE CSE GATE ECE GATE EE GATE ME GATE CE GATE PI GATE IN GATE Data Science and Artificial Intelligence
Civil Services
UPSC Civil Service
Defence
NDA
Staff Selection Commission
SSC CGL Tier I
CBSE
Class 12