Before You Begin
Question #42757
The Question
A rigid symmetric dipole is modeled as a symmetric top with moment of inertia about its symmetry axis and about any transverse axis passing through its center of mass. The dipole has a permanent electric dipole moment directed along its symmetry axis. It is placed in a uniform electric field directed along the positive Z-axis. Initially, the symmetry axis of the dipole is held at an angle with respect to the Z-axis. The dipole is given an initial spin angular velocity about its symmetry axis such that (where and ), and then released such that its initial nutation and precession angular velocities are zero. Find the maximum magnitude of the precession angular velocity (where is the azimuthal angle around the Z-axis) of the dipole during its subsequent motion. Assume no non-conservative forces are acting on the system.
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Multi-Concept_Bridge
Master problems that require linking physics and math concepts to solve complex competitive questions.
Concepts Behind This Question
Work Done in Rotating Dipole|Gyroscopic Stability|Vector Cross-Product
Why This Question Is Tricky
Common Mistakes
This question tests the advanced application of rigid body dynamics, specifically the gyroscopic motion of a symmetric top in a potential field.
The primary trap lies in assuming the dipole undergoes steady precession () from the moment of release, which incorrectly yields (Option B).
Students often fail to recognize that releasing the dipole from rest (zero initial precession) induces nutation, and the work done by the electric field couples into both the nutational and precessional kinetic energies.
By forcing the use of Euler's equations or Lagrangian conservation laws ( and ), the problem discriminates between students who memorize the steady precession formula and those who understand the full dynamical evolution of the angular momentum vector in non-inertial frames.
Quick Facts About This Question
Question Information
| Subject | Physics |
| Chapter | Electrostatic Potential and Capacitance - Class 12 |
| Concept | Work Done in Rotating Dipole |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |