Coulomb\'s law gives us the force on a point charge, Q, due to a single point ch
ID: 1884879 • Letter: C
Question
Coulomb's law gives us the force on a point charge, Q, due to a single point charge, q, at rest a distance r away where o 8.85 x 10F/m is the vacuum permittivity, k 8.99x 10 N m IC is the Coulomb constant, and is the unit vector giving the direction from q to Q If we have lots of source charges (Qetc) then to find the force on Q we use the principle of superposition. That is, we just add up the forces from each individual source charge on Q. We can write this simply as The source charges are said to create an electric field, E which is a function of position because the vectors r, depend on the location of Q, and the configuration of the source charges. The electric field is more than just an intermediate step in calculating electric forces. You can think of it as a real physical entity filling the space in the neighbourhood of any electric charge. Here is a representation of the electric field around two opposite charges (dipole) using an array of vectors Comment on the variation of vector length and direction. Which charge is positive? You can also connect up the arrows to form field lines. You haven't thrown away the information about the magnitude of the field at each point because it is contained in the density of the field lines: Number of lines from each particle indicates its charge magnitude - compare the charges here? Comment on spacing of lines on surface of particles, direction of arrows, crossing of lines etcExplanation / Answer
(1) First Figure:
In the first figure, the red colored point at which a positive charge situated because the field lines are moving away from it. Similarly, the blue colored point represents a negative charge; field line converging towards it.
(2) Second figure:
Both the red and blue point has the same magnitude of charge and are opposite in nature. This is because the same number of field lines are originating from both the charges. In regions where the electric field lines are equally spaced, there is the same number of lines per unit area everywhere, and the electric field has the same strength at all points. The direction of arrows indicates the direction of the dipole moment. It is important to note that any two line never cross each other because it indicates two different dipole moment from same two charges.