JEE Mains · Physics · STD 11 - 9.2 surface tension
A water drop of diameter \(cm\) is broken into \(64\) equal droplets. The surface tension of water is \(0.075\,N / m\). In this process the gain in surface energy will be ...........\(J\)
- A \(2.8 \times 10^{-4}\)
- B \(1.5 \times 10^{-3}\)
- C \(1.9 \times 10^{-4}\)
- D \(9.4 \times 10^{-5}\)
Answer & Solution
Correct Answer
(A) \(2.8 \times 10^{-4}\)
Step-by-step Solution
Detailed explanation
\(d =2\,cm ; \quad r =1\,cm ; \quad T =0.075\) \(\Delta SE = T \Delta A\) \(=0.075\left( A _{ f }- A _{1}\right)\) \(A _{ i }=4 \pi r ^{2}\) \(A _{ t }=4 \pi r _{0}^{2} \times 64\) By volume conservation \(\frac{4}{3} \pi r ^{3}=64 \cdot \frac{4}{3} \pi r_{0}^{3}\)…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- The frequency of oscillation of a mass \(m\) suspended by a spring is \(v_1\). If the length of the spring is cut to half, the same mass oscillates with frequency \(v_2\). The value of \(v_2/v_1\) is ________.JEE Mains 2026 Medium
- Three identical charged balls each of charge \(2 \,C\) are suspended from a common point \(P\) by silk threads of \(2 \,m\) each (as shown in figure). They form an equilateral triangle of side \(1 \,m\). The ratio of net force on a charged ball to the force between any two charged balls will be ...........
JEE Mains 2022 Hard - A displacement current of \(4.0\) A can be set up in the space between two parallel plates of \(6\) \(\mu\)F capacitor. The rate of change of potential difference across the plates of the capacitor is nearly \(\alpha \times 10^6\) V/s. The value of \(\alpha\) is __________.JEE Mains 2026 Easy
- An \(AC\) source rated \(220\, V , 50\, Hz\) is connected to a resistor. The time taken by the current to change from its maximum to the rms value isJEE Mains 2021 Medium
- The excess pressure inside a soap bubble A in air is half the excess pressure inside another soap bubble B in air. If the volume of the bubble A is \(n\) times the volume of the bubble \(B\), then, the value of \(n\) is ___.JEE Mains 2025 Easy
- A particle of charge \(q\) and mass \(m\) is projected from origin with an initial velocity \(\vec{v} = \left(\dfrac{v_0}{\sqrt{2}}\hat{x} + \dfrac{v_0}{\sqrt{2}}\hat{y}\right)\). There exists a uniform magnetic field \(\vec{B} = B_0 \hat{z}\) and a space varying electric field \(\vec{E} = E_0 e^{-\lambda x}\hat{x}\) within the region \(0 \leq x \leq L\). After travelling a distance such that \(x\)-coordinate has changed from \(x=0\) to \(x=L\), the change in the kinetic energy is _______.JEE Mains 2026 Hard
More PYQs from JEE Mains
- Slope of a line passing through \(P(2, 3)\) and intersecting the line, \(x + y = 7\) at a distance of \(4\) units from \(P,\) isJEE Mains 2019 Hard
- A circular hole of radius \(\frac{R}{4}\) is made in a thin uniform disc having mass \(M\) and radius \(R\), as shown in figure. The moment of inertia of the remaining portion of the disc about an axis passing through the point \(O\) and perpendicular to the plane of the disc is
JEE Mains 2017 Hard - Let \(y=y(t)\) be a solution of the differential equation \(\frac{d y}{d t}+\alpha y=\gamma e^{-\beta t}\) Where, \(\alpha > 0, \beta > 0\) and \(\gamma > 0\). Then \(\operatorname{Lim}_{t \rightarrow \infty} y(t)\)JEE Mains 2023 Hard
- If \(\alpha, \beta,\) where \(\alpha<\beta\), are the roots of the equation \(\lambda x^{2}-(\lambda+3)x+3=0\) such that \(\frac{1}{\alpha}-\frac{1}{\beta}=\frac{1}{3},\) then the sum of all possible values of \(\lambda\) is:JEE Mains 2026 Medium
- If the equations \(x^2 + bx - 1 = 0\) and \(x^2 + x + b= 0\) have a common root different from \(-1,\) then \(\left| b \right|\) is equal toJEE Mains 2016 Hard
- Let \(A\) be a symmetric matrix of order \(2\) with integer entries. If the sum of the diagonal elements of \(A ^{2}\) is \(1,\) then the possible number of such matrices isJEE Mains 2021 Medium