JEE Advanced · 2011 · 10 Apr 2011 · Paper 1 · Elasticity & SHM

WhatsApp Email
Phase space diagrams are useful tools in analyzing all kinds of dynamical problems. They are especially useful in studying the changes in motion as initial position and momentum are changed. Here we consider some simple dynamical systems in one-dimension. For such systems, phase space is a plane in which position is plotted along horizontal axis and momentum is plotted along vertical axis. The phase space diagram is x(t) vs. p(t) curve in this plane. The arrow on the curve indicates the time flow. For example, the phase space diagram for a particle moving with constant velocity is a straight line as shown in the figure. We use the sign convention in which position or momentum upwards (or to right) is positive and downwards (or to left) is negative.

The phase space diagram for simple harmonic motion is a circle centered at the origin. In the figure, the two circles represent the same oscillator but for different initial conditions, and and are the total mechanical energies respectively. Then
  1. (A)
  2. (B)
  3. (C)✓ Correct
  4. (D)

Answer: (C)

Solution

For simple harmonic motion, the phase space trajectory is an ellipse (or circle with appropriate scaling). The energy is proportional to the square of the amplitude.

From the figure, the radius of the larger circle appears to be twice that of the smaller circle. Since energy (where A is amplitude):



Therefore, .

JEE Advanced · 2011 · 10 Apr 2011 · Paper 1 · Single correct option

More JEE Advanced questions on Elasticity & SHM

  1. A tank contains two immiscible liquids of densities and . The higher density liquid is filled up to a height from the bottom. A thin rod of density and length is fully immersed and hinged at the bottom so that it can oscillate freely, as shown …
    JEE Advanced 2026View solution →
  2. The center of a disk of radius and mass is attached to a spring of spring constant , inside a ring of radius as shown in the figure. The other end of the spring is attached on the periphery of the ring. Both the ring and the disk are in the same vertical …
    JEE Advanced 2025View solution →
  3. As shown in the figures, a uniform rod of length is hinged at the point and held in place vertically between two walls using two massless springs of same spring constant. The springs are connected at the midpoint and at the top-end of the rod, as show …
    JEE Advanced 2025View solution →
  4. Two beads, each with charge and mass , are on a horizontal, frictionless, non-conducting, circular hoop of radius . One of the beads is glued to the hoop at some point, while the other one performs small oscillations about its equilibrium position along the hoop. …
    JEE Advanced 2024View solution →
  5. A block of mass 5 kg moves along the x-direction subject to the force , with the value of in metre. At time , it is at rest at position . The position and momentum of the block at ar …
    JEE Advanced 2024View solution →
  6. Two point-like objects of masses 20 gm and 30 gm are fixed at the two ends of a rigid massless rod of length 10 cm. This system is suspended vertically from a rigid ceiling using a thin wire attached to its center of mass, as shown in the figure. The resulting torsional pendulum …
    JEE Advanced 2023View solution →