The magnitude of the E field, also known as electric field strength, is a measure of the force per unit charge exerted on a test charge at a specific point in space. It is typically measured in units of newtons per coulomb (N/C) or volts per meter (V/m).
The magnitude of the E field can be calculated using the equation E = F/q, where E is the electric field strength, F is the force exerted on the test charge, and q is the magnitude of the test charge. It can also be calculated using the equation E = kQ/r^2, where k is the Coulomb's constant, Q is the charge of the source, and r is the distance between the source and the test charge.
The direction of the E field is defined as the direction that a positive test charge would experience a force when placed in the field. It is always directed away from positive charges and towards negative charges. Additionally, the direction of the E field is perpendicular to the equipotential surfaces, which are imaginary surfaces that connect points with the same electric potential.
The direction of the E field is typically represented using electric field lines. These lines are drawn in a way that the tangent to the line at any point gives the direction of the E field at that point. The lines originate from positive charges and terminate on negative charges. The closer the lines are together, the stronger the E field at that point.
Yes, the direction of the E field can change depending on the location and orientation of the source charges. It is also affected by the presence of other charges or conductors in the surrounding space. The E field can also change direction as the distance from the source changes. However, the magnitude of the E field remains constant in a vacuum as long as the source charge remains the same.