Electric Field Intensity Due To a Finite Line Charge - Field Theory.
- Consider a line charge with uniform charge density ρ L extending from + a to – a along the z- axis. - Charge element dQ associated with the element dl of the line is dQ = ρ L dl = ρ L dz - From the diagram it’s clear that the Electric field intensity has two components i.e. E ρ and E z . - If we move around the line charge and if we vary ρ , while keeping φ and z constant, it is expected that the field would become weaker as ρ increases. - No element of charge produces a φ component i.e. E φ is equal to zero. - Hence Electric field intensity at point P has only two component one along the ρ and the other along the z direction. - However the contribution due to E z component by the elements of charge will be canceled because the same are at equal distances above and below the point at which the field is to be determined. ( For Example: If a charge element is present at + 4a z and another charge element at - 4a z , then the z compone...