Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Advanced 2012Paper 1
Exam
JEE Advanced
Year
2012
Paper
Paper 1
Subject
Physics
Chapter
Rotational Motion

JEE Advanced 2012 · Paper 1 · Physics · Rotational Motion

A small mass m is attached to a massless string whose other end is...

A small mass mm is attached to a massless string whose other end is fixed at PP as shown in the figure. The mass is undergoing circular motion in the x−yx-y plane with centre at OO and constant angular speed ω\omega. If the angular momentum of the system, calculated about OO and PP are denoted by L⃗O\vec{L}_{O} and L⃗P\vec{L}_{P} respectively, then A small mass m is attached to a massless string whose other end is fixed at P as shown in the figure. The mass is

Options

  1. AL⃗O\vec{L}_{O} and L⃗P\vec{L}_{P} do not vary with time
  2. BL⃗O\vec{L}_{O} varies with time while L⃗P\vec{L}_{P} remains constant
  3. CL⃗O\vec{L}_{O} remains constant while L⃗P\vec{L}_{P} varies with time
  4. DL⃗O\vec{L}_{O} and L⃗P\vec{L}_{P} both vary with time

Correct answer

C. L⃗O\vec{L}_{O} remains constant while L⃗P\vec{L}_{P} varies with time

Step-by-step solution

For all locations of m\mathrm{m} the angular momentum of the mass mm about OO i.e., LoL_{o} is mr2ωm r^{2} \omega and is directed toward +z+z direction. The angular momentum of mass mm about PP i.e., LpL_{p} is mvlm v l and is directed for the given location of mm as shown in the figure. For different location of mm, the direction of L⃗P\vec{L}_{P} remains changing. A small mass m is attached to a massless string whose other end is fixed at P as shown in the figure. The mass is
Practice Rotational Motion on Quantrex Academy →

More from Rotational Motion

Consider a large disk of radius R and two smaller disks, each of radius r = R/50 , lying… JEE Advanced 2026A solid cylinder of radius R rolls without slipping with a center of mass speed v_0 =… JEE Advanced 2026List-I shows four planar structures made of uniform solid rods each of mass m and length… JEE Advanced 2026Passage: A uniform circular disk of radius 0.2 m and mass 1 kg is pivoted at its top… JEE Advanced 2026Passage: A uniform circular disk of radius 0.2 m and mass 1 kg is pivoted at its top… JEE Advanced 2026A solid cylinder having radius R and length L is slipping on a rough horizontal plane. At… JEE Main 2026A solid sphere ( A ) of mass 5m and a spherical shell ( B ) of mass m , both having same… JEE Main 2026A solid sphere of radius 4 cm and mass 5 kg is rotating (rotation axis is passing through… JEE Main 2026 Full Rotational Motion list All JEE Advanced PYQs