ExamBro
ExamBro
JEE Advanced · Physics · 17. Electrostatics

A disk of radius R with uniform positive charge density σ is placed on the xy plane with its center at the origin. The Coulomb potential along the z-axis is
Vz=σ2ϵ0R2+z2-z A particle of positive charge q is placed initially at rest at a point on the z-axis with z=z0 and z0>0. In addition to the Coulomb force, the particle experiences a vertical force F=-ck^ with c>0. Let β=2cε0qσ. Which of the following statement(s) is(are) correct?

  1. A For β=14 and z0=257R, the particle reaches the origin.
  2. B For β=14 and z0=37R, the particle reaches the origin.
  3. C For β=14 and z0=R3, the particle returns back to z=z0
  4. D For β>1 and z0>0, the particle always reaches the origin.
Verified Solution

Answer & Solution

Correct Answer

(A) For β=14 and z0=257R, the particle reaches the origin.

Step-by-step Solution

Detailed explanation

For the particle to reach at origin, work done by the force should be greater than the increase in the potential energy of the charged particle. Therefore, czσq2ϵ0R-R2+z2-zc2ϵ0σqR-R2+z2-zzβR-R2+z2-zz
Same subject
Explore more questions on app
From JEE Advanced
Explore more questions on app