- 1(current)
Q. No.Consider a water tank shown in the figure. It has one wall at \(x=L\) and can be taken to be very wide in the \(z\) direction. When filled with a liquid of surface tension \(S\) and density \(\rho,\) the liquid, surface makes angle \(\theta_{0}\left(\theta_0 \ll 1\right)\) with the \(x\text-\)axis at \(x=L.\) If \(y(x)\) is the height of the surface then the equation for \(y(x)\) is:
(take \(\theta(x)=\sin \theta(x)=\tan \theta(x)=\dfrac{d y}{d x}, g\) is the acceleration due to gravity)
(take \(\theta(x)=\sin \theta(x)=\tan \theta(x)=\dfrac{d y}{d x}, g\) is the acceleration due to gravity)
| 1. | \(\dfrac{d^2 y}{d x^2}=\sqrt{\dfrac{\rho g}{S}}\) | 2. | \(\dfrac{d y}{d x}=\sqrt{\dfrac{\rho g}{S}} x\) |
| 3. | \(\dfrac{d^2 y}{d x^2}=\dfrac{\rho g}{S} x\) | 4. | \(\dfrac{d^2 y}{d x^2}=\dfrac{\rho g}{S} y\) |
Subtopic: Â Surface Tension |
Level 4: Below 35%
NEET - 2025
Please attempt this question first.
Hints
Please attempt this question first.
A wire of length \(L\) and radius \(r(r\ll L)\) is kept floating on the surface of a liquid of density \(\rho.\) The maximum radius of the wire for which it may not sink is:
(the surface tension of liquid is \(T\))
(the surface tension of liquid is \(T\))
| 1. | \(\sqrt { \dfrac{T}{\rho g}}\) | 2. | \(\sqrt { \dfrac{2T}{\rho g}}\) |
| 3. | \(\sqrt{\dfrac{2T\rho}{\pi g}}\) | 4. | \(\sqrt{\dfrac{2T} {\pi \rho g}}\) |
Subtopic: Â Surface Tension |
 60%
Level 2: 60%+
NEET - 2024
Hints
A thin flat circular disc of radius \(4.5~\text {cm}\) is placed gently over the surface of water. If the surface tension of water is \(0.07~\text{Nm}^{-1},\) then the excess force required to take it away from the surface is:
1. \(198~\text{N}\)
2. \(1.98~\text{mN}\)
3. \(99~\text{N}\)
4. \(19.8~\text{mN}\)
1. \(198~\text{N}\)
2. \(1.98~\text{mN}\)
3. \(99~\text{N}\)
4. \(19.8~\text{mN}\)
Subtopic: Â Surface Tension |
 53%
Level 3: 35%-60%
NEET - 2024
Hints
The amount of energy required to form a soap bubble of radius \(2~\text{cm}\) from a soap solution is nearly:
\((\)the surface tension of soap solution \(0.03~\text{Nm}^{-1})\)
1. \(50.1 \times 10^{-4}~\text{J}\)
2. \(30.16 \times 10^{-4}~ \text{J}\)
3. \(5.06 \times 10^{-4} ~\text{J}\)
4. \(3.01\times 10^{-4} ~\text{J}\)
\((\)the surface tension of soap solution \(0.03~\text{Nm}^{-1})\)
1. \(50.1 \times 10^{-4}~\text{J}\)
2. \(30.16 \times 10^{-4}~ \text{J}\)
3. \(5.06 \times 10^{-4} ~\text{J}\)
4. \(3.01\times 10^{-4} ~\text{J}\)
Subtopic: Â Surface Tension |
 63%
Level 2: 60%+
NEET - 2023
Hints
If a soap bubble expands, the pressure inside the bubble:
1. is equal to the atmospheric pressure
2. decreases
3. increases
4. remains the same
1. is equal to the atmospheric pressure
2. decreases
3. increases
4. remains the same
Subtopic: Â Surface Tension |
 70%
Level 2: 60%+
NEET - 2022
Hints
A soap bubble, having a radius of \(1~\text{mm}\), is blown from a detergent solution having a surface tension of \(2.5\times 10^{-2}~\text{N/m}\). The pressure inside the bubble equals at a point \(Z_0\) below the free surface of the water in a container. Taking \(g = 10~\text{m/s}^{2}\), the density of water \(= 10^{3}~\text{kg/m}^3\), the value of \(Z_0\) is:
1. \(0.5~\text{cm}\)
2. \(100~\text{cm}\)
3. \(10~\text{cm}\)
4. \(1~\text{cm}\)
Subtopic: Â Surface Tension |
 58%
Level 3: 35%-60%
NEET - 2019
Hints
Links
A certain number of spherical drops of a liquid of radius \({r}\) coalesce to form a single drop of radius \({R}\) and volume \({V}.\) If \({T}\) is the surface tension of the liquid, then:
| 1. | the energy \(= 4{VT}\left( \frac{1}{{r}} - \frac{1}{{R}}\right)\) is released. |
| 2. | the energy \(={ 3{VT}\left( \frac{1}{{r}} + \frac{1}{{R}}\right)}\) is released. |
| 3. | the energy \(={ 3{VT}\left( \frac{1}{{r}} - \frac{1}{{R}}\right)}\) is released. |
| 4. | the energy is neither released nor absorbed. |
Subtopic: Â Surface Tension |
 75%
Level 2: 60%+
AIPMT - 2014
Hints
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Q. No.
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