JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion
\(5\,g\) and radius \(1\,cm\) is fixed to a thin stick \(AB\) of negligible mass as shown in the figure. The system is initially at rest. The constant torque, that will make the system rotate about \(AB\) at \(25\) rotations per second in \(5\,s\) is close to
- A \(2.0\times 10^{-5}\,Nm\)
- B \(4.0\times 10^{-6}\,Nm\)
- C \(1.6\times 10^{-5}\,Nm\)
- D \(7.9\times 10^{-6}\,Nm\)
Answer & Solution
Correct Answer
(A) \(2.0\times 10^{-5}\,Nm\)
Step-by-step Solution
Detailed explanation
\(m = 5 \times {10^{ - 3}}kg,\,\,\,r = {10^{ - 2}}m\) \(\omega = 25 \times 2\pi \,rad/5\) \( = 50\,\,\pi \,\,rad/\sec \) \(\omega = \frac{\tau }{I}t\) \(\tau = \frac{{I\omega }}{t} = \frac{{5m{r^2}}}{4} \times \frac{\omega }{t}\)…
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
- A car of \(800 \mathrm{~kg}\) is taking turn on a banked road of radius \(300 \mathrm{~m}\) and angle of banking \(30^{\circ}\). If coefficient of static friction is \(0.2\) then the maximum speed with which car can negotiate the turn safely which? \(\left(\mathrm{g}=10 \mathrm{~m} / \mathrm{s}^2, \sqrt{3}=1.73\right)\)JEE Mains 2024 Hard
- Water is flowing at a speed of \(1.5\, ms^{-1}\) through a horizontal tube of cross-sectional area \(10^{-2}\, m^2\) and you are trying to stop the flow by your palm. Assuming that the water stops immediately after hitting the palm. the minimum force that you must exert should be ......... \(N\) (density of water \(= 10^3\, kgm^{-3}\))JEE Mains 2014 Medium
- A wire \(X\) of length \(50\; cm\) carrying a current of \(2\,A\) is placed parallel to a long wire \(Y\) of length \(5\,m\). The wire \(Y\) carries a current of \(3\,A\). The distance between two wires is \(5\,cm\) and currents flow in the same direction. The force acting on the wire \(Y\) is.
JEE Mains 2022 Medium - A uniform cylinder of mass \(M\) and radius \(R\) is to be pulled over a step of height \(a (a < R\)) by applying a force \(F\) at its centre \('O'\) perpendicular to the plane through the axes of the cylinder on the edge of the step ( see figure). The minimum value of \(F\) required is
JEE Mains 2020 Hard - From a solid sphere of mass \(M\) and radius \(R\), a spherical portion of radius \(R/2\) is removed, as shown in the figure. Taking gravitational potential \(V = 0\) at \(r = \infty\), the potential at the centre of the cavity thus formed is
( \(G =\) gravitational constant)
JEE Mains 2015 Hard - In a Young's double slit experiment, slits are separated by \(0.5\ mm\), and the screen is placed \(150\ cm\) away. A beam of light consisting of two wavelengths, \(650\ nm\) and \(520\ nm\), is used to obtain interference fringes on the screen. The least distance from the common central maximum to the point where the bright fringes due to both the wavelengths coincide is...... \(mm\)JEE Mains 2017 Medium
More PYQs from JEE Mains
- Two cylindrical rods A and B made of different materials, are joined in a straight line. The ratio of lengths, radii and thermal conductivities of these rods are :
\(\frac{\mathrm{L}_{\mathrm{A}}}{\mathrm{L}_{\mathrm{B}}}=\frac{1}{2}, \frac{\mathrm{r}_{\mathrm{A}}}{\mathrm{r}_{\mathrm{B}}}=2\) and \(\frac{\mathrm{K}_{\mathrm{A}}}{\mathrm{K}_{\mathrm{B}}}=\frac{1}{2}\). The free ends of rods A and B are maintained at \(400 \mathrm{~K}, 200 \mathrm{~K}\), respectively. The temperature of rods interface is ________ K, when equilibrium is established.JEE Mains 2025 Hard - Let \([t]\) be the greatest integer less than or equal to \(t\). Let \(A\) be the set of al prime factors of \(2310\) and \(f: A \rightarrow \mathbb{Z}\) be the function \(f(x)=\left[\log _2\left(x^2+\left[\frac{x^3}{5}\right]\right)\right]\). The number of one-to-one functions from \(A\) to the range of \(f\) is :JEE Mains 2024 Hard
- A particle is moving in a circular path of radius \(a,\) with a constant velocity \(v\) as shown in the figure.The centre of circle is marked by \('C'\). The angular momentum from the origin \(O\) can be written as
JEE Mains 2014 Hard - The number of non-empty equivalence relations on the set \(\{1,2,3\}\) is :JEE Mains 2025 Easy
- A juggler throws balls vertically upwards with same initial velocity in air. When the first ball reaches its highest position, he throws the next ball. Assuming the juggler throws \(n\) balls per second, the maximum height the balls can reach isJEE Mains 2022 Medium
- Let \(f ( x )\) be a quadratic polynomial with leading coefficient \(1\) such that \(f(0)=p, p \neq 0\) and \(f(1)=\frac{1}{3}\). If the equation \(f(x)=0\) and \(fofofof (x)=0\) have a common real root, then \(f(-3)\) is equal to \(........\)JEE Mains 2022 Hard