JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion
As shown in figure, when a spherical cavity (centred at \(\mathrm{O})\) of radius \(1\) is cut out of a uniform sphere of radius \(\mathrm{R} \text { (centred at } \mathrm{C}),\) the centre of mass of remaining (shaded) part of sphere is at \(G\), i.e, on the surface of the cavity. \(\mathrm{R}\) can be detemined by the equation

- A \(\left(\mathrm{R}^{2}-\mathrm{R}+1\right)(2-\mathrm{R})=1\)
- B \(\left(\mathrm{R}^{2}+\mathrm{R}-1\right)(2-\mathrm{R})=1\)
- C \(\left(\mathrm{R}^{2}+\mathrm{R}+1\right)(2-\mathrm{R})=1\)
- D \(\left(\mathrm{R}^{2}-\mathrm{R}-1\right)(2-\mathrm{R})=1\)
Answer & Solution
Correct Answer
(C) \(\left(\mathrm{R}^{2}+\mathrm{R}+1\right)(2-\mathrm{R})=1\)
Step-by-step Solution
Detailed explanation
By concept of \(COM\) \(\mathrm{m}_{1} \mathrm{R}_{1}=\mathrm{m}_{2} \mathrm{R}_{2}\) Remaining mass \(\times(2-\mathrm{R})=\) cavity mass \(\times(\mathrm{R}-1)\)…
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
- pendulum made of a uniform wire of cross sectional area \(A\) has time period \(T\). When an additional mass \(M\) is added to its bob, the time period changes to \(T_M\). If the Young's modulus of the material of the wire is \(Y\) then \(\frac{1}{Y}\) is equal to : (\(g\) = gravitational acceleration)JEE Mains 2015 Hard
- A stationary source emits sound waves of frequency \(500\, Hz\). Two observers moving along a line passing through the source detect sound to be of frequencies \(480\, Hz\) and \(530\, Hz\). Their respective speeds are, in \(m\,s^{-1}\) (Given speed of sound \(= 300\, m/s\))JEE Mains 2019 Medium
- Following plots show Magnetization \((M)\) \(vs\) Magnetising field \((H)\) and Magnetic susceptibility \((\chi)\) vs temperature \((T)\) graph : Which of the following combination will be represented by a diamagnetic material?
JEE Mains 2021 Medium - To establish an instantaneous current of \(2\,A\) through a \(1\,\mu F\) capacitor ; the potential difference across the capacitor plates should be changed at the rate ofJEE Mains 2013 Medium
- The energy dissipated by a resistor is \(10 \,mJ\) in \(1\,s\) when an electric current of \(2\, mA\) flows through it. The resistance is \(....... \Omega\) (Round off to the Nearest Integer)JEE Mains 2021 Easy
- The magnetic field in a plane electromagnetic wave is \(\mathrm{B}_y=\left(3.5 \times 10^{-7}\right) \sin \left(1.5 \times 10^3 \mathrm{x}+0.5\right.\) \(\left.\times 10^{11} \mathrm{t}\right) \mathrm{T}\). The corresponding electric field will be _______.JEE Mains 2024 Hard
More PYQs from JEE Mains
- Consider the function. \(f(x)=\left\{\begin{array}{cc} \frac{a\left(7 x-12-x^2\right)}{b\left|x^2-7 x+12\right|} & , x<3 \\ 2^{\frac{\sin (x-3)}{x-[x]}} & , x>3 \\ b & , x=3 \end{array}\right.\) Where \([\mathrm{x}]\) denotes the greatest integer less than or equal to \(x\). If \(S\) denotes the set of all ordered pairs \((a, b)\) such that \(f(x)\) is continuous at \(x=3\), then the number of elements in \(\mathrm{S}\) is :JEE Mains 2024 Hard
- The typical output characteristics curve for a transistor working in the common-emitter configuration is shown in the figure. The estimated current gain from the figure is
JEE Mains 2021 Medium - If the line \(\alpha x+2y=1\), where \(\alpha\in\mathbb{R}\), does not meet the hyperbola \(x^{2}-9y^{2}=9\), then a possible value of \(\alpha\) is:JEE Mains 2026 Medium
- Three small identical bubbles of water having same charge on each coalesce to form a bigger bubble. Then the ratio of the potentials on one initial bubble and that on the resultant bigger bubble is:JEE Mains 2026 Hard
- A projectile fired at \(30^{\circ}\) to the ground is observed to be at same height at time \(3 s\) and \(5 s\) after projection, during its flight. The speed of projection of the projectile is \(.........\,ms ^{-1}\)(Given \(g=10\,m s ^{-2}\) )JEE Mains 2023 Hard
- The normal to the curve \(y\left( {x - 2} \right)\left( {x - 3} \right) = x + 6\) at the point where the curve intersects the \(y - \)axis passes through the point :JEE Mains 2017 Medium