Physics · Mechanical Properties of Matter

JEE Main 2026 — 21 January, Evening Shift — Question 37

Surface tension of two liquids (having same densities), T1\mathrm{T}_{1} and T2\mathrm{T}_{2}, are measured using capillary rise method utilizing two tubes with inner radii of r1r_{1} and r2r_{2} where r1>r2r_{1}>r_{2}. The measured liquid heights in these tubes are h1\mathrm{h}_{1} and h2\mathrm{h}_{2} respectively. [Ignore the weight of the liquid about the lowest point of miniscus]. The heights h1\mathrm{h}_{1} and h2\mathrm{h}_{2} and surface tensions T1\mathrm{T}_{1} and T2\mathrm{T}_{2} satisfy the relation :

  1. Option A:

    h1<h2\mathrm{h}_{1}<\mathrm{h}_{2} and T1=T2\mathrm{T}_{1}=\mathrm{T}_{2}

    Correct
  2. Option B:

    h1=h2\mathrm{h}_{1}=\mathrm{h}_{2} and T1=T2\mathrm{T}_{1}=\mathrm{T}_{2}

  3. Option C:

    h1>h2\mathrm{h}_{1}>\mathrm{h}_{2} and T1=T2\mathrm{T}_{1}=\mathrm{T}_{2}

  4. Option D:

    h1>h2h_{1}>h_{2} and T1<T2T_{1}<T_{2}

Answer: A

Step-by-step solution

h=2Tρgrh=\frac{2 T}{\rho g r} h∝1r\mathrm{h} \propto \frac{1}{\mathrm{r}} If r1>r2⇒ h2>h1\mathrm{r}_{1}>\mathrm{r}_{2} \Rightarrow \mathrm{~h}_{2}>\mathrm{h}_{1}

Answer key and solution verified before publishing.

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Exam
JEE Main 2026
Subject
Physics
Chapter
Mechanical Properties of Matter
Topic
Surface Tension and Surface Energy
Surface tension of two liquids (having same densities), T 1 and T 2 … | JEE Main 2026 PYQ with Solution · DhiX AI