The electric field just outside the surface of a conductor is normal to the surface. Why?

Why electric fields just outside the surface of a conductor is perpendicular to the surface?

"Electric field lines always meet the surface of a conductor normally" - justify the statement.

Show that electric field intenstity on the surface of a charged conductor is vecE=sigma/ε_0 vecn where sigma is the surface density of charge and vecn is the outward pointing unit normal vector.

Careful measurement of the electric field at the surface of a black box indicates that the net outward flux through the surface ofthe box is 8.0x10^3Nm^2//C . What is the net charge inside the box ?

Careful measurement of the electric field at the surface of a black box indicates that the net outward flux through the surface ofthe box is 8.0x10^3Nm^2//C . If the net outward flux through the surface of the box were zero, could you conclude that there were nd charges inside the box ? Why or why not ?

Careful measurement of the electric field at the surface of a black box indicates that the net outward flux through the surface of the box is 8.0 xx 10^(3)N*m^(2)*C^(-1) . (a) What is the net charge inside the box? (b) If the net outward flux through the surface of the box where zero, could you conclude that there where no charges inside the box? Why or why not ?

The direction of electrostatic field intensity at a point on the surface of a charged conductor is along the tangent drawn on the surface at that point . Is the statement true or false ?

An electric is expressed as vecE=20 hatiV.m^(-1) . Find the electric flux passing through a surface of area 0.25m^(2) normal to the x-axis.