Two Long Charged Thin-Walled Concentric Cylinders

Delving into the realm of electromagnetism, we embark on an exploration of two long charged thin-walled concentric cylinders. These cylindrical structures possess unique electrical properties that have garnered significant interest in various scientific and engineering applications.

Our journey begins with an examination of the electric field distribution between the cylinders, followed by an investigation into the system’s capacitance. We will delve into the factors that influence capacitance and explore the energy storage capabilities of these cylinders.

Electrostatic Field between Cylinders

Concentric cylinders

The electric charges on the surfaces of the cylinders are distributed uniformly. The electric field between the cylinders is radial and its magnitude is given by:

$$E = \frac\lambda2\pi\epsilon_0 r$$

where

  • λ is the linear charge density on the cylinders
  • ε 0is the permittivity of free space
  • r is the distance from the axis of the cylinders

The boundary conditions for the electric field are:

  • E = 0 at r = a
  • E = λ/(2πε 0b) at r = b

where a and b are the radii of the inner and outer cylinders, respectively.

Capacitance of the System

Two long charged thin-walled concentric cylinders

The capacitance of the system is defined as the ratio of the charge on the cylinders to the potential difference between them. It is given by:

$$C = \frac2\pi\epsilon_0 L\ln(b/a)$$

where L is the length of the cylinders.

The capacitance of the system is affected by the following factors:

  • The radii of the cylinders
  • The length of the cylinders
  • The permittivity of the medium between the cylinders

Energy Stored in the System

Concentric charged radii spherical inner qa

The energy stored in the electric field between the cylinders is given by:

$$U = \frac12CV^2$$

where V is the potential difference between the cylinders.

The relationship between capacitance and energy storage is that the energy stored in the system is directly proportional to the capacitance.

Applications of the System

Two long charged thin-walled concentric cylinders

Two long charged thin-walled concentric cylinders are used in a variety of practical applications, including:

  • Capacitors
  • Electrostatic filters
  • Particle accelerators

The advantages of using this system in different applications include:

  • High capacitance
  • Low inductance
  • Compact size

The disadvantages of using this system include:

  • High voltage requirements
  • Potential for arcing
  • Limited current-carrying capacity

Potential future applications of the system include:

  • Energy storage
  • Wireless power transmission
  • Electrostatic propulsion

Commonly Asked Questions: Two Long Charged Thin-walled Concentric Cylinders

What is the significance of the boundary conditions in determining the electric field between the cylinders?

Boundary conditions are essential in solving the Laplace equation for the electric field. They ensure that the electric field satisfies the physical constraints of the system, such as the continuity of the electric field and the absence of charges outside the cylinders.

How does the capacitance of the system depend on the radii of the cylinders?

The capacitance is inversely proportional to the natural logarithm of the ratio of the outer radius to the inner radius. As the radii of the cylinders increase, the capacitance decreases.

What are some potential applications of two long charged thin-walled concentric cylinders?

These cylinders find applications in high-voltage power transmission lines, particle accelerators, and medical imaging devices such as MRI scanners.