JEE Mains · Physics · STD 11 - 9.2 surface tension
A capillary tube of radius 0.1 mm is partly dipped in water (surface tension \(70 \mathrm{dyn} / \mathrm{cm}\) and glass water contact angle \(\simeq 0^{\circ}\)) with \(30^{\circ}\) inclined with vertical. The length of water risen in the capillary is ________ cm.
\(\left(\right.\) Take \(\left.\mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^2\right)\)
- A \(\frac{82}{5}\)
- B \(\frac{57}{2}\)
- C \(\frac{71}{5}\)
- D \(\frac{68}{5}\)
Answer & Solution
Correct Answer
(A) \(\frac{82}{5}\)
Step-by-step Solution
Detailed explanation
\begin{aligned} & \mathrm{h}=\frac{2 \mathrm{~T} \cos \theta}{\rho \mathrm{gr}}=\frac{2 \times 70 \times 1}{1 \times 980 \times 10^{-2}} \\ & \mathrm{~h}=\frac{100}{7} \mathrm{~cm} \\ & \sin 60^{\circ}=\frac{\mathrm{h}}{\ell} \\ & \ell=\frac{\mathrm{h} \times 2}{\sqrt{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 resistive network shown below is connected to a \(D.C.\) source of \(16\, V\). The power consumed by the network is \(4\, Watt\). The value of \(R\) is ............. \(\Omega\)
JEE Mains 2019 Medium - In an \(n-p-n\) common emitter (\(CE\)) transistor the collector current changes from \(5\,mA\) to \(16\,mA\) for the change in base current from \(100\,\mu A\) and \(200\,\mu A\), respectively. The current gain of transistor isJEE Mains 2023 Easy
- Preeti reached the metro station and found that the escalator was not working. She walked up the stationary escalator in time \(t_1\) . On other days, if she remains stationary on the moving escalator, then the escalator takes her up in time \(t_2\). The time taken by her to walk up on the moving escalator will beJEE Mains 2021 Medium
- For a plane electromagnetic wave, the magnetic field at a point \(x\) and time \(t\) is \(\overrightarrow{ B }( x , t )=\left[1.2 \times 10^{-7} \sin \left(0.5 \times 10^{3} x +1.5 \times 10^{11} t \right) \hat{ k }\right] T\) The instantaneous electric field \(\overrightarrow{ E }\) corresponding to \(\overrightarrow{ B }\) is : (speed of light \(\left.c=3 \times 10^{8} ms ^{-1}\right)\)JEE Mains 2020 Medium
- Arrange the following in the ascending order of wavelength \((\lambda)\) :
(A) Microwaves \(\left(\lambda_1\right)\)
(B) Ultraviolet rays \(\left(\lambda_2\right)\)
(C) Infrared rays \(\left(\lambda_3\right)\)
(D) X-rays \(\left(\lambda_4\right)\)
Choose the most appropriate answer from the options given below :JEE Mains 2025 Medium - A wire of length \(L\) and radius \(r\) is clamped rigidly at one end. When the other end of the wire is pulled by a force \(f\), its length increases by \(l\). Another wire of same material of length \(2 L\) and radius \(2 r\) is pulled by a force \(2 f\). Then the increase in its length will beJEE Mains 2023 Medium
More PYQs from JEE Mains
- The position of a particle as a function of time \(t\), is given by \(x\left( t \right) = at+ b{t^2} - c{t^3}\) where \(a, b\) and \(c\) are constants. When the particle attains zero acceleration, then its velocity will beJEE Mains 2019 Hard
- Let \(\vec{a}=\hat{i}-\hat{j}+2 \hat{k}\) and \(\vec{b}\) be a vector such that \(\vec{a} \times \vec{b}=2 \hat{i}-\hat{k}\) and \(\vec{a} \cdot \vec{b}=3\). Then the projection of \(\vec{b}\) on the vector \(\vec{a}-\vec{b}\) is :-JEE Mains 2022 Medium
- In a double slit experiment, when a thin film of thickness \(t\) having refractive index \(\mu \) is introduced in front of one of the slits, the maximum at the centre of the fringe pattern shifts by one fringe width. The value of \(t\) is (\(\lambda \) is the wavelength of the light used)JEE Mains 2019 Medium
- Let \(A =\left(\begin{array}{cc} m & n \\ p & q \end{array}\right), d =| A | \neq 0| A - d (\operatorname{Adj} A )|=0\). ThenJEE Mains 2023 Hard
- Let \(z\) be a complex number such that the real part of \(\frac{z-2 i}{z+2 i}\) is zero. Then, the maximum value of \(|\mathrm{z}-(6+8 \mathrm{i})|\) is equal to :JEE Mains 2024 Hard
- \(N\,moles\) of a diatomic gas in a cylinder are at a temperature \(T\). Heat is supplied to the cylinder such that the temperature remains constant but \(n\,moles\) of the diatomic gas get converted into monoatomic gas. What is the change in the total kinetic energy of the gas ?JEE Mains 2017 Medium