The "E-field of a moving charge at constant velocity" refers to the electric field that is produced by a charged particle as it moves at a constant velocity. This field is responsible for the movement and interaction of other charged particles within its vicinity.
The strength of the E-field is directly proportional to the velocity of the charge. As the charge moves faster, the E-field becomes stronger, and as it slows down, the E-field weakens.
The direction of the E-field is always perpendicular to the velocity of the charge. This means that if the charge is moving in a straight line, the E-field will be in a circular pattern around the charge.
When the charge changes direction, the E-field also changes direction accordingly. This is because the E-field is always perpendicular to the velocity of the charge.
The E-field of a moving charge is stronger and more complex compared to that of a stationary charge. This is because the moving charge creates a changing electric field that affects the surrounding space, while a stationary charge only creates a static electric field.