JEE Mains · Physics · STD 11 - Gravitation
- JEE Mains 2021
- Medium
- MCQ
The angular momentum of a planet of mass \(M\) moving around the sun in an elliptical orbit is \(\overrightarrow{ L }\). The magnitude of the areal velocity of the planet is:
Pick an option to check your answer.
Answer & Solution
Correct Answer
(D) \(\frac{L }{2M }\)
Step-by-step Solution
Detailed explanation
For small displacement ds of the planet its area can be written as
\(d A =\frac{1}{2} rd \ell\)
\(=\frac{1}{2} r d s \sin \theta\)
A.vel \(=\frac{ d A }{ dt }=\frac{1}{2} r \sin \theta \frac{ ds }{ dt }=\frac{ Vr \sin \theta}{2}\)
\(\frac{ d A }{ dt }=\frac{1}{2} \frac{ mVr \sin \theta}{ m }=\frac{ L }{2 m }\)
More questions from Physics
- A small ball of mass \(M\) and density \(\rho\) is dropped in a viscous liquid of density \(\rho_0\). After some time, the ball falls with a constant velocity. What is the viscous force on the ball ?JEE Mains 2023 Medium
- As per the given figure, if \(\frac{ dI }{ dt }=-1 A / s\) then the value of \(V _{ AB }\) at this instant will be \(................V\).
JEE Mains 2023 Medium - A large drum having radius \(R\) is spinning around its axis with angular velocity \(\omega\), as shown in figure. The minimum value of \(\omega\) so that a body of mass M remains stuck to the inner wall of the drum, taking the coefficient of friction between the drum surface and mass M is \(\mu\), is :
JEE Mains 2026 Hard - Two identical springs of spring constant \('2k'\) are attached to a block of mass \(m\) and to fixed support (see figure). When the mass is displaced from equilibrium position on either side, it executes simple harmonic motion. The time period of oscillations of this sytem is ...... .
JEE Mains 2021 Medium - If \(\mathrm{G}\) be the gravitational constant and \(\mathrm{u}\) be the energy density then which of the following quantity have the dimension as that the \(\sqrt{\mathrm{uG}}\)?JEE Mains 2024 Hard
- An ideal gas undergoes a quasi static, reversible process in which its molar heat capacity \(C\) remains constant. If during this process the relation of pressure \(P\) and volume \(V\) is given by \(PV^n =\) constant, then n is given by (Here \(C_p\) and \(C_v\) are molar specific heat at constant pressure and constant volume, respectively) :JEE Mains 2016 Hard
More PYQs from JEE Mains
- As shown in the figure, a particle of mass \(10\) \(kg\) is placed at a point \(A\). When the particle is slightly displaced to its right, it starts moving and reaches the point \(B\). The speed of the particle at \(B\) is \(x\, m / s\). (Take \(\left. g =10\, m / s ^{2}\right)\) The value of \('x'\) to the nearest integer is.........
JEE Mains 2021 Medium - A circuit connected to an \(ac\) source of \(emf\) \(e = e_0\, sin\, (1000t)\) with \(t\) in seconds, gives a phase difference of \(\frac{\pi }{4}\) between the \(emf\) \(e\) and current \(i\). Which of the following circuits will exhibit this?JEE Mains 2019 Hard
- Three charges +2q. +3q and -4q are situated at (0,-3a), (2a, 0) and (-2a,0) respectively in the xy plane. The resultant dipole moment about origin is _________JEE Mains 2026 Easy
- A ring of mass \(M\) and radius \(R\) is rotating about its axis with angular velocity \(\omega \). Two identical bodies each of mass \(m\) are now gently attached at the two ends of a diameter of the ring. Because of this, the kinetic energy loss will beJEE Mains 2013 Hard