Home
Class 12
PHYSICS
Consider an evacuated cylindrical chambe...

Consider an evacuated cylindrical chamber of height h having rigid conducting plates at the ends and an insulating curved surface as shown in the figure. A number of spherical balls made of a light weight and soft material and coated with a conducting material are placed on the bottom plate. The balls have a radius `r lt lt h`. Now a high voltage source (HV) is connected across the conducting plates such that the bottom plate is at `+V_0` and the top plate at `-V_0`. Due to their conducting surface, the balls will get charged, will become equipotential with the plate and are repelled by it. The balls will eventually collide with the top plate, where the coefficient of restitution can be taken to be zero due to the soft nature of the material of the balls. The electric field in the chamber can be considered to be that of a parallel plate capacitor. Assume that there are no collisions between the balls and the interaction between them is negligible. (Ignore gravity)

Which one of the following statements is correct?

A

(a) The balls will stick to the top plate and remain there

B

(b) The balls will bounce back to the bottom plate carrying the same charge they went up with

C

(c) The balls will bounce back to the bottom plate carrying the opposite charge they went up with

D

(d) The balls will execute simple harmonic motion between the two plates

Text Solution

Verified by Experts

The correct Answer is:
C

After colliding the top plate, the ball will gain negative charge and get repelled by the top plate and bounce back to the bottom plate.
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • ELECTROSTATICS

    SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise Subjective Problems|2 Videos
  • ELECTROMAGNETIC INDUCTION AND ALTERNATING CURRENT

    SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise JEE Main And Advanced|107 Videos
  • MODERN PHYSICS

    SUNIL BATRA (41 YEARS IITJEE PHYSICS)|Exercise MCQ (One Correct Answer|1 Videos

Similar Questions

Explore conceptually related problems

A non conducting ring of radius R is charged as shown in figure : Figure

Consider an evacuted cylindrical chamber of height h having rigid conducting plates at the end and an insulting curved surface as shown in the figure. A number of spherical balls made of a light weight and soft material and coated with a conducting material are placed on the bottom plated. The balls have a radius r The average current in the steady state registered by the ammeter in the circuit will be

Knowledge Check

  • Consider an evacuated cylindrical chamber of hight h rigid conducting plates at the ends and an insulating curved surgace as shown in the figure. A number of spherical balls madeof a light weight and soft material and coagted with a conducting material are placed on the bottom plate. The balls have a radius rltlth . Now a high voltage source (HV) is connected across the conducting plates such that th ebottom plate is at+V_(0) and the top plate at-V_(0) . Due to their conducting surface the balls will get charged, will become equipotential with the plate and are repelled by it. The balls will eventually collide with the top plate, where the coefficient of reatitution can be taken to be zero due to the soft nature of the material of the balls. The electric field in the chamber can be considered to be considered to be that of a parallel plate capacitor. Assume tht there are no collisions between the balls and the interaction between them is negligible. (Ignore gravity) Which one of the following statements is correct ?

    A
    The balls will execute simple harmonic motion between the two plates
    B
    The balls will bounce back to the bottom plate carrying the opposite charge they went up with
    C
    The balls will bounce back to the bottom plate carrying the same charge they went up with
    D
    The balls will stick to the top plate and remain there
  • Consider an evacuated cylindrical chamber of hight h rigid conducting plates at the ends and an insulating curved surgace as shown in the figure. A number of spherical balls madeof a light weight and soft material and coagted with a conducting material are placed on the bottom plate. The balls have a radius rltlth . Now a high voltage source (HV) is connected across the conducting plates such that th ebottom plate is at+V_(0) and the top plate at-V_(0) . Due to their conducting surface the balls will get charged, will become equipotential with the plate and are repelled by it. The balls will eventually collide with the top plate, where the coefficient of reatitution can be taken to be zero due to the soft nature of the material of the balls. The electric field in the chamber can be considered to be considered to be that of a parallel plate capacitor. Assume tht there are no collisions between the balls and the interaction between them is negligible. (Ignore gravity) The average current in the steady state registered by the ammeter in the circuit will be

    A
    proportional to `V_(0)^(2)`
    B
    proportional to `V_(0)^(1//2)`
    C
    proportional to the potential `V_(0)`
    D
    zero
  • Consider an evacuted cylindrical chamber of height h having rigid conducting plates at the end and an insulting curved surface as shown in the figure. A number of spherical balls made of a light weight and soft material and coated with a conducting material are placed on the bottom plated. The balls have a radius r Which one of the following statements is correct?

    A
    The balls will stick to the top plate and remain there
    B
    The balls will bounce back to the bottom plate carrying the same charge they went up with
    C
    The balls will bounce back to the bottom plate carrying the opposite charge they went up with
    D
    The balls will execute simple harmonic motion between the two plates
  • Similar Questions

    Explore conceptually related problems

    The thermal conductivity of a plate depends on

    Shown in the figure a spherical shell with an inner radius 'a' and an outer radius 'b' is made of conducting metarial. A charge +Q is placed at the centre of the spherical shell and a total charge -q s placed on the shell. Charge -q is districuted on the surfaces as :

    A cylindrical rod of iron whose height is eight times its radius is melted and cast into spherical balls each of half the radius of the cylinder. The number of such spherical balls is

    Two conducting shells of radius a and b are connected by conducting wire as shown in figure. The capacity of system is :

    Two conducting shells of radius a and bare connected by conducting wire as shown in figure. The capacitance of this system is :