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JEE Physics 2025 Question with Solution

Match List-I with List-II.

A matching-list table showing physical quantities in List-I and dimensional formulas or units in List-II, to be matched item by item.

Choose the correct answer from the options given below:

  • A

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

  • B

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

  • C

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

  • D

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

Answer

Correct answer:D

Step-by-step solution

Standard Method

Given: A match-the-following question between List-I and List-II.

Find: The correct option by using dimensional analysis.

From the solution:

  • (A) Young's Modulus has dimensions of stress, since strain is dimensionless.
ForceArea=MLT−2L2=ML−1T−2\frac{\text{Force}}{\text{Area}} = \frac{MLT^{-2}}{L^2} = ML^{-1}T^{-2}
  • (B) Torque is force multiplied by distance.
MLT−2×L=ML2T−2MLT^{-2} \times L = ML^2T^{-2}
  • (C) Coefficient of Viscosity is obtained from viscous force per unit area divided by velocity gradient.
η=ML−1T−2T−1=ML−1T−1\eta = \frac{ML^{-1}T^{-2}}{T^{-1}} = ML^{-1}T^{-1}
  • (D) Gravitational Constant from Newton's law of gravitation is
G=Fr2m1m2=(MLT−2)L2M2=M−1L3T−2G = \frac{Fr^2}{m_1m_2} = \frac{(MLT^{-2})L^2}{M^2} = M^{-1}L^3T^{-2}

the solution is internally inconsistent: one place states The Correct Option is D, another line says Thus, the correct answer is option (4), while the detailed working lists matches that do not align with the visible options. Since the solution explicitly declares The Correct Option is D, that is taken.

Therefore, the correct option is D.

Solution

Given: The source solution contains a hint and two approaches.

Find: Which option should be marked correct.

The hint says to use dimensional analysis to match physical quantities with their units or dimensional formulas.

In the solution, the strongest explicit conclusion shown is:

  • The Correct Option is D

Although the subsequent working contains mismatches and inconsistent final mappings, the instruction is to prefer the explicit conclusion from the solution when present.

Hence, the answer is recorded as D.

Common mistakes

  • Students may treat stress as having dimensions MLT−2MLT^{-2} instead of force per unit area. This is wrong because area contributes an extra L2L^2 in the denominator. Always divide force by area before writing the dimensional formula.

  • Students may confuse torque with force and forget the extra factor of distance. This is wrong because torque equals force multiplied by perpendicular distance. So an extra LL must appear in the dimensional formula.

  • Students may use the raw option list or provided correct-answer field without checking the solution. This is risky because provided pages can contain inconsistencies. First derive or confirm the result from the solution working and explicit conclusion.

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