JEE Mains · Physics · STD 11 - System of particles and rotational motion
- JEE Mains 2015
- Hard
- MCQ
Distance of the centre of mass of a solid uniform cone from its vertex is \(z_0\) . If the radius of its base is \(R\) and its height is \(h\) then \(z_0\) is equal to
Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) \(\frac{{3h}}{4}\)
Step-by-step Solution
Detailed explanation
\(\begin{array}{l}
{y_{cm}} = \frac{{\int {ydm} }}{{\int {dm} }}\\
\,\,\,\,\,\,\,\, = \frac{{\int\limits_0^h {\pi {r^2}dy\rho \times y} }}{{\frac{1}{3}\pi {R^2}h\rho }} = \frac{{3h}}{4}
\end{array}\)

{y_{cm}} = \frac{{\int {ydm} }}{{\int {dm} }}\\
\,\,\,\,\,\,\,\, = \frac{{\int\limits_0^h {\pi {r^2}dy\rho \times y} }}{{\frac{1}{3}\pi {R^2}h\rho }} = \frac{{3h}}{4}
\end{array}\)

More questions from Physics
- Find the magnetic field at point \(P\) due to a straight line segment \(AB\) of length \(6\, cm\) carrying a current of \(5\, A\). (See figure) \((\mu _0 = 4p\times10^{-7}\, N-A^{-2})\)
JEE Mains 2019 Hard - Find the equivalent resistance between two ends of the following circuit
JEE Mains 2025 Easy - A bus moving along a straight highway with speed of \(72 \mathrm{~km} / \mathrm{h}\) is brought to halt within \(4 \mathrm{~s}\) after applying the brakes. The distance travelled by the bus during this time (Assume the retardation is uniform) is __________\(\mathrm{m}\).JEE Mains 2024 Hard
- A coil in the shape of an equilateral triangle of side \(10\, {cm}\) lies in a vertical plane between the pole pieces of permanent magnet producing a horizontal magnetic field \(20\, {mT}\). The torque acting on the coil when a current of \(0.2\, {A}\) is passed through it and its plane becomes parallel to the magnetic field will be \(\sqrt{{x}} \times 10^{-5} \,{Nm}\). The value of \({x}\) is ..... .JEE Mains 2021 Medium
- charge \(Q\) is uniformly distributed over a long rod \(AB\) of length \(L\) as shown in the figure. The electric potential at the point \(O\) lying at distance \(L\) from the end \(A\) is
JEE Mains 2013 Medium - A point charge of \(10^{-8} C\) is placed at origin. The work done in moving a point charge \(2 \mu C\) from point \(A (4,4,2) m\) to \(B (2,2,1) m\) is _________ J.JEE Mains 2026 Easy
More PYQs from JEE Mains
- A point charge \(q = 1\ \mu\text{C}\) is located at a distance \(2\text{ cm}\) from one end of a thin insulating wire of length \(10\text{ cm}\) having a charge \(Q = 24\ \mu\text{C}\), distributed uniformly along its length, as shown in figure. Force between \(q\) and wire is _______ N.
(Use \(\frac{1}{4\pi\varepsilon_0} = 9 \times 10^9\text{ N}\cdot\text{m}^2/\text{C}^2\))
JEE Mains 2026 Easy - A transistor is used in an amplifier circuit in common emitter mode. If the base current changes by \(100 \,\mu A\), it brings a change of \(10 \,mA\) in collector current. If the load resistance is \(2 \,k \Omega\) and input resistance is \(1 \,k \Omega\), the value of power gain is \(x \times 10^{4}\). The value of \(x\) is_________JEE Mains 2022 Medium
- Two identical thin metal plates has charge \(q _{1}\) and \(q _{2}\) respectively such that \(q _{1}> q _{2}\). The plates were brought close to each other to form a parallel plate capacitor of capacitance \(C\). The potential difference between them is.JEE Mains 2022 Medium
- For a periodic motion represented by the equation \(Y=\sin \omega t+\cos \omega t\) The amplitude of the motion isJEE Mains 2023 Easy
- At a certain place the angle of dip is \(30^{\circ}\) and the horizontal component of earth's magnetic field is \(0.5 G\). The earth's total magnetic field (in \(G\) ), at that certain place, is ................JEE Mains 2022 Easy