JEE Mains · Physics · STD 11 - 9.1 fluid mechanics
Suppose you have taken a dilute solution of oleic acid in such a way that its concentration becomes \(0.01 \,cm ^{3}\) of oleic acid per \(cm ^{3}\) of the solution. Then you make a thin film of this solution (monomolecular thickness) of area \(4\, cm ^{2}\) by considering \(100\) spherical drops of radius \(\left(\frac{3}{40 \pi}\right)^{\frac{1}{3}} \times 10^{-3}\, cm .\) Then the thickness of oleic acid layer will be \(x \times 10^{-14} \,m\). Where \(x\) is ...... .
- A \(30\)
- B \(25\)
- C \(20\)
- D \(36\)
Answer & Solution
Correct Answer
(B) \(25\)
Step-by-step Solution
Detailed explanation
\(4 t _{ T }=100 \times \frac{4}{3} \pi r ^{3}\) \(=100 \times \frac{4 \pi}{3} \times \frac{3}{40 \pi} \times 10^{-9}=10^{-8}\, cm ^{3}\) \(t _{ T }=25 \times 10^{-10}\, cm\) \(=25 \times 10^{-12} \,m\) \(t _{0}=0.01 t _{ T }=25 \times 10^{-14}\, m\) \(=25\)
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
- This question has statement \(1\) and statement \(2\) . Of the four choices given after the statements, choose the one that best describes the two statements.
Statement \(- 1\): A point particle of mass m moving with speed \(u\) collides with stationary point particle of mass \(M\). If the maximum energy loss possible is given as \(f\) \(\left( {\frac{1}{2}m{v^2}} \right)\) then \( f = \left( {\frac{m}{{M + m}}} \right)\) Statement \(-2\): Maximum energy loss occurs when the particles get stuck together as a result of the collision.JEE Mains 2013 Medium - \(A\) and \(B\) are two sources generating sound waves. A listener is situated at \(C\) . The frequency of the source at \(A\) is \(500\,Hz\) . \(A,\) now, moves towards \(C\) with a speed \(4\,m/s.\) The number of beats heard at \(C\) is \(6.\) When \(A\) moves away from \(C\) with speed \(4\,m/s,\) the number of beats heard at \(C\) is \(18.\) The speed of sound is \(340\,m/s.\) The frequency of the source at \(B\) is ..... \(Hz\)
JEE Mains 2013 Medium - A rod of length \(60 \mathrm{~cm}\) rotates with a uniform angular velocity \(20 \mathrm{rad} \mathrm{s}^{-1}\) about its perpendicular bisector, in a uniform magnetic field \(0.5 \mathrm{~T}\). The direction of magnetic field is parallel to the axis of rotation. The potential difference between the two ends of the rod is________\(V\).JEE Mains 2024 Hard
- The moment of inertia of a solid disc rotating along its diameter is 2.5 times higher than the moment of inertia of a ring rotating in similar way. The moment of inertia of a solid sphere which has same radius as the disc and rotating in similar way, is \(n\) times higher than the moment of inertia of the given ring. Here, \(\mathrm{n}=\)_________
Consider all the bodies have equal masses.JEE Mains 2025 Hard - The difference of temperature in a material can convert heat energy into electrical energy. To harvest the heat energy, the material should have _________.JEE Mains 2025 Easy
- The electric field in an electromagnetic wave is given by \(E =56.5 \sin \omega( t - x / c ) \;NC ^{-1}\). Find the intensity of the wave if it is propagating along \(x-\)axis in the free space. (Given \(\left.\varepsilon_{0}=8.85 \times 10^{-12} \;C ^{2} N ^{-1} m ^{-2}\right)\)JEE Mains 2022 Medium
More PYQs from JEE Mains
- Let \(ABCD\) be a quadrilateral. If \(E\) and \(F\) are the mid points of the diagonals \(AC\) and \(BD\) respectively and \((\overrightarrow{ AB }-\overline{ BC })+(\overrightarrow{ AD }-\overrightarrow{ DC })= k \overline{ FE }\), then \(k\) is equal toJEE Mains 2023 Hard
- If for positive integers \(r> 1, n > 2\), the coefficients of the \((3r)^{th}\) and \((r + 2)^{th}\) powers of \(x\) in the expansion of \(( 1 + x)^{2n}\) are equal, then \(n\) is equal toJEE Mains 2013 Hard
- \(f(x)=4 \log _{e}(x-1)-2 x^{2}+4 x+5, x>1\), which one of the following is NOT correct?JEE Mains 2022 Hard
- As shown in the figure, a potentiometer wire of resistance \(20\,\Omega\) and length \(300\,cm\) is connected with resistance box (R.B.) and a standard cell of emf \(4\,V\). For a resistance ' \(R\) ' of resistance box introduced into the circuit, the null point for a cell of \(20\,mV\) is found to be \(60\,cm\). The value of ' \(R\) ' is \(.....\Omega\)
JEE Mains 2022 Medium - A source of sound emits sound waves at frequency \(f_0\). It is moving towards an observer with fixed speed \(v_s\) (\(v_s < v\), where \(v\) is the speed of sound in air). If the observer were to move towards the source with speed \(v_0\), one of the following two graphs (\(A\) and \(B\)) will given the correct variation of the frequency \(f\) heard by the observer as \(v_0\) is changed The variation of \(f\) with \(v_0\) is given correctly by
JEE Mains 2015 Easy - A convex lens made of glass (refractive index \(=1.5\) ) has focal length 24 cm in air. When it is totally immersed in water (refractive index \(=1.33\) ), its focal length changes to ________.JEE Mains 2025 Medium