JEE Mains · Physics · STD 12 - Ray optics and optical instruments
- JEE Mains 2021
- Hard
- Numerical
A glass tumbler having inner depth of \(17.5\, {cm}\) is kept on a table. A student starts pouring water \((\mu=4 / 3)\) into it while looking at the surface of water from the above. When he feels that the tumbler is half filled, he stops pouring water. Up to what height, the tumbler is actually filled ? (In \(cm\))
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(10\)
Step-by-step Solution
Detailed explanation
Height of water observed by observer
\(=\frac{{H}}{\mu_{{w}}}=\frac{{H}}{(4 / 3)}=\frac{3 {H}}{4}\)
Height of air observed by observer \(=17.5-{H}\) According to question, both height observed by observer is same.
\(\frac{3 {H}}{4}=17.5-{H}\)
\(\Rightarrow {H}=10\, {cm}\)
More questions from Physics
- A wooden block of mass \(5 \mathrm{~kg}\) rests on soft horizontal floor. When an iron cylinder of mass \(25\) \(\mathrm{kg}\) is placed on the top of the block, the floor yields and the block and the cylinder together go down with an acceleration of \(0.1 \mathrm{~ms}^{-2}\). The action force of the system on the floor is equal to _______.JEE Mains 2024 Hard
- Two equal capacitors are first connected in series and then in parallel. The ratio of the equivalent capacities in the two cases will beJEE Mains 2021 Medium
- The electric field in a region of space is given by, \(\overrightarrow E = {E_0}\hat i + 2{E_0}\hat j\) where \(E_0\, = 100\, N/C\). The flux of the field through a circular surface of radius \(0.02\, m\) parallel to the \(Y-Z\) plane is nearlyJEE Mains 2014 Hard
- According to kinetic theory of gases, \(A\). The motion of the gas molecules freezes at \(0^{\circ} C\) \(B\). The mean free path of gas molecules decreases if the density of molecules is increased. \(C\). The mean free path of gas molecules increases if temperature is increased keeping pressure constant. \(D\). Average kinetic energy per molecule per degree of freedom is \(\frac{3}{2} k_{B} T\) (for monoatomic gases) Choose the most appropriate answer from the options given belowJEE Mains 2022 Medium
- A solid cylinder is released from rest from the top of an inclined plane of inclination \(30^{\circ}\) and length \(60\,cm\). If the cylinder rolls without slipping, its speed upon reaching the bottom of the inclined plane is \(...........ms ^{-1}\). (Given \(g =10\,ms ^{-2}\))
JEE Mains 2023 Medium - For a transparent prism, if the angle of minimum deviation is equal to its refracting angle, the refractive index n of the prism satisfies.JEE Mains 2026 Easy
More PYQs from JEE Mains
- A photon of wavelength \(\lambda \) is scattered from an electron, which was at rest. The wavelength shift \(\Delta \lambda \) is three times of \( \lambda \) and the angle of scattering \(\theta \) is \(60^o\) . The angle at which the electron recoiled is \(\phi \). The value of \(tan\,\phi \) is : ( electron speed is much smaller than the speed of light)JEE Mains 2014 Hard
- 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
- One end of a metal wire is fixed to a ceiling and a load of \(2 \mathrm{~kg}\) hangs from the other end. A similar wire is attached to the bottom of the load and another load of \(1 \mathrm{~kg}\) hangs from this lower wire. Then the ratio of longitudinal strain of upper wire to that of the lower wire will be _______. [Area of cross section of wire \(=0.005 \mathrm{~cm}^2\), \(\mathrm{Y}=2 \times 10^{11}\ \mathrm{Nm}^{-2}\) and \(\left.\mathrm{g}=10 \mathrm{~ms}^{-2}\right]\)JEE Mains 2024 Hard
- In the following circuit, the magnitude of current \(I _{ l }\), is \(............A\).
JEE Mains 2023 Hard - A \(0.4\,kg\) mass takes \(8 s\) to reach ground when dropped from a certain height ' \(P\) ' above surface of earth. The loss of potential energy in the last second of fall is \(..............J\). [Take \(g =10\,m / s ^2\) ]JEE Mains 2023 Medium