electric charges and fields

• Electric field lines always point away from positive charges and towards negative charges.
• Outside a charged conductor, the electric field lines end on the surface of the conductor.
• Inside a conductor, there are no free electrons or protons, so the net charge inside is zero.
• The strength of the electric field is proportional to the charge density, with higher densities resulting in stronger fields.
• An electric field line starts from a positive charge and ends at a negative charge or leaves the system if there is no opposite charge present.
• Electric field lines are imaginary lines that represent the direction and strength of an electric field at any given point.
• Coulomb's law explains how electric charges influence each other by exerting forces of attraction or repulsion.
• The force between two point charges is directly proportional to the product of their magnitudes, inversely proportional to the square of the distance between them, and depends on the signs of the charges.
• The proportionality constant in Coulomb's law is known as the permittivity of free space.
• Coulomb's law states that the electrostatic force between two charged particles is proportional to the product of their charges and inversely proportional to the square of the distance between them.
• The electric potential at a point in an electric field is the amount of work done per unit charge in bringing a positive test charge from infinity to that point.
• The electric potential is zero at infinity and increases as you move closer to a positive charge.
• Inside a charged conductor, there is no electric field because all free charge has moved to the surface.
• The direction of an electric field line can be found by placing a small test charge at any point along the line and observing its motion under the influence of the electric force.
• If the test charge moves toward the source of the field, then the field points away from that source; if it moves away from the source, then the field points toward the source.
• The electric field lines inside a conductor form closed loops around any regions with non-zero charge density.
• If an object has a uniformly distributed charge, then the electric field at all points outside it will be perpendicular to its surface.
• A dipole consists of two equal but opposite charges separated by some distance.
• Charge density can be calculated using the formula Q/V, where Q is the total charge and V is the volume occupied by that charge.
• Surface charge density is the amount of charge per unit area on an object's surface.
• Line charge density refers to the amount of charge per unit length along a line.
• A closed loop of electric field lines indicates that the total charge enclosed by the loop is zero.
• Like charges repel each other, while unlike charges attract.
• If an object has a non-zero charge, it will experience a force due to its interaction with other objects' electric fields.
• Like charges repel each other, while unlike charges attract each other.
• Field lines never cross as this would imply two different directions of force acting on a test charge placed at that location.
• The force between two stationary objects depends only on their relative positions and not on their motion.
• A closed loop of field lines indicates a region where the electric field is uniform (constant).
• A conductor is a material through which electricity can flow easily due to its high conductivity.
• A charged object can be neutralized by adding equal amounts of opposite charges until it has zero net charge.
• If the field lines become closer together, it means the electric field is getting stronger.
• A charged object can be represented as having a positive charge equal to its total charge minus the amount of negative charge it has.
• If one object has more than one charge, then the total force acting on it will be equal to the vector sum of all individual forces acting on it.
• Like charges repel each other while unlike charges attract each other.
• When two objects have different amounts of charge but the same sign, they will experience a greater attractive force than when they have the same amount of charge but opposite signs.
• When two like-charged objects approach each other, they experience a repulsive force.
• The electric potential difference (voltage) between two points is equal to the change in potential energy per unit charge when moving a charge between those points.
• Charge conservation states that the total amount of charge in a closed system remains unchanged over time.
• Electric flux is defined as the number of lines passing through a given area normal to the direction of the field.
• A capacitor consists of two conductors separated by an insulator called a dielectric.