Induction of Charge: Why & How Does it Occur?

  • Thread starter Thread starter greatscott
  • Start date Start date
  • Tags Tags
    Charge Induction
AI Thread Summary
When a point charge of +q is placed near an infinite conducting plane, it induces a net charge of -q on the surface of the plane. This occurs because the free electrons in the conductor move in response to the electric field created by the point charge, resulting in a redistribution of charge. Although this movement creates a surface charge, the overall conductor remains electrically neutral. The induced charge refers specifically to the charge that appears on the surface of the conductor due to this redistribution, which is measured as -q. The concept of induced charge differs from the net charge of the conductor, which remains zero. The electric field within the conductor becomes zero, while the field at the surface is perpendicular to the surface.
greatscott
Messages
14
Reaction score
0
When a point charge of +q is put near a conducting infinite plane, net charge of -q is induced on the plane. Why and how does this occur? I thought that although the charges (free electrons) in the conductor will move (so that the electrons are closer to the point charge), the net charge of the plane will still be zero.
 
Physics news on Phys.org
There will be net charge on the surface of the conductor but the conductor will remain net neutral. The conduction electrons throughout the conductor redistribute themselves such that there is no electric field within the conductor and field at the surface is normal to the surface.
 
The book says "the total charge induced on the plane is -q." Maybe "induced charge on the plane" means something different from the net charge of the plane? How is "induced charge" measured?
 
greatscott said:
The book says "the total charge induced on the plane is -q." Maybe "induced charge on the plane" means something different from the net charge of the plane? How is "induced charge" measured?

Tide answered that already:

Tide said:
There will be net charge on the surface of the conductor...

Tide said:
but the conductor will remain net neutral.
 
This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'
Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
Back
Top