zoki85 said:Perhaps q0 denotes a test charge? Then the force on that charge in electric field is denoted as F0.
The equation for electric field is E = F/q, where E is the electric field, F is the force exerted on a charged particle, and q is the charge of the particle.
The electric field is calculated by dividing the force exerted on a charged particle by the charge of the particle. This can also be written as E = kQ/r^2, where k is the Coulomb's constant, Q is the source charge, and r is the distance between the source charge and the point where the electric field is being calculated.
The unit of electric field is Newtons per Coulomb (N/C) in the SI system. In the CGS system, the unit is dynes per statcoulomb (dyn/esu).
The electric field is inversely proportional to the square of the distance between the source charge and the point where the electric field is being calculated. This means that as the distance increases, the electric field decreases.
The direction of the electric field at a point is the direction in which a positive test charge would move if placed at that point. This is important because it helps us understand the direction of the force exerted on a charged particle in an electric field.