force experienced by a charge q in electric field E is
Answers
Explanation:
A field is a way of explaining action at a distance. Massive particles attract each other. How do they do this, if they are not in contact with each other? We say that massive particles produce gravitational fields. A field is a condition in space that can be probed. Massive particle are also the probes that detect a gravitational field. A gravitational field exerts a force on massive particles. The magnitude of the gravitational field produced by a massive object at a point P is the gravitational force per unit mass it exerts on another massive object located at that point. The direction of the gravitational field is the direction of that force The magnitude of the gravitational force near the surface of Earth is F = mg, the gravitational field has magnitude F/m = g. Its direction is downward.
Charged particles attract or repel each other, even when not in contact with each other. We say that charged particles produce electric fields. Charged particles are also the probes that detect an electric field. An electric field exerts a force on charged particles. The magnitude of the electric field E produced by a charged particle at a point P is the electric force per unit positive charge it exerts on another charged particle located at that point. The direction of the electric field is the direction of that force on a positive charge. The actual force on a particle with charge q is given by F = qE. It points in the opposite direction of the electric field E for a negative charge. In the presence of many other charges, a charge q is acted on by a net force F, which is the vector sum of the forces due to all the other charges. The electric field due to all the other charges at the position of the charge q is E = F/q, i.e. it is the vector sum of the electric fields produce by all the other charges. To measure the electric field E at a point P due to a collection of charges, we can bring a small positive charge q to the point P and measure the force on this test charge. The test charge must be small, because it interacts with the other charges, and we want this interaction to be small. We divide the force on the test charge by the magnitude of the test charge to obtain the field.
Consider a point charge Q located at the origin. The force on a test charge q at position r is F = (keQq/r2) (r/r). The electric field produced by Q is E = F/q = (keQ/r2) (r/r). If Q is positive, then the electric field points radially away from the charge. The electric field decreases with distance as 1/(distance)2. electric field of a negative chargeIf Q is negative, then the electric field points radially towards the charge.The electric field decreases with distance as 1/(distance)2. We obtain the electric field due to a collection of charges using the principle of superposition.
E = E(Q1) + E(Q2) + E(Q3) + ... .
Field lines were introduced by Michael Faraday to help visualize the direction and magnitude of he electric field. The direction of the field at any point is given by the direction of a line tangent to the field line, while the magnitude of the field is given qualitatively by the density of field lines. The field lines converge at the position of a point charge. Near a point charge their density becomes very large. The magnitude of the field and the density of the field lines scale as the inverse of the distance squared.
Field lines start on positive charges and end on negative charges.
Rules for drawing field lines:
Electric field lines begin on positive charges and end on negative charges, or at infinity.
Lines are drawn symmetrically leaving or entering a charge.
The number of lines entering or leaving a charge is proportional to the magnitude of the charge.
The density of lines at any point (the number of lines per unit length perpendicular to the lines themselves) is proportional to the field magnitude at that point.
At large distances from a system of charges, the field lines are equally spaced and radial as if they came from a single point charge equal in magnitude to the net charge on the system (presuming there is a net charge).
No two field lines can cross, since the field magnitude and direction must be unique.