Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 202126 FebruaryMorning Shift
Exam
JEE Main
Year
2021
Date
26 February
Shift
Morning Shift
Subject
Physics
Chapter
Rotational Motion

JEE Main 2021 · 26 February · Morning Shift · Physics · Rotational Motion

Four identical solid spheres each of mass m and radius a are placed...

Four identical solid spheres each of mass mm and radius aa are placed with their centres on the four corners of a square of side bb. The moment of inertia of the system about one side of square where the axis of rotation is parallel to the plane of the square is :Four identical solid spheres each of mass m and radius a are placed with their centres on the four corners of a square

Options

  1. A85ma2+mb2\dfrac{8}{5}m{a}^{2} + m{b}^{2}
  2. B45ma2+2mb2\dfrac{4}{5}m{a}^{2} + 2m{b}^{2}
  3. C85ma2+2mb2\dfrac{8}{5}m{a}^{2} + 2m{b}^{2}
  4. D45ma2\dfrac{4}{5}m{a}^{2}

Correct answer

C. 85ma2+2mb2\dfrac{8}{5}m{a}^{2} + 2m{b}^{2}

Step-by-step solution

Four identical solid spheres each of mass m and radius a are placed with their centres on the four corners of a square

I=2×(25ma2)+2×(25ma2+mb2)I = 2 \times \left(\dfrac{2}{5}m{a}^{2}\right) + 2 \times \left(\dfrac{2}{5}m{a}^{2} + m{b}^{2}\right)

I=85ma2+2mb2I = \dfrac{8}{5}m{a}^{2} + 2m{b}^{2}

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 Main PYQs