Electric field just outside a charged conductor is perpendicular to the surface and has a magnitude σ/2ε.
a. true
b. false

The answer is False

Explanation:

For a infinite sheet of charges, the electric field is perpendicular to its surface. To calculate the electric field, we use a Gaussian surface (cylinder), getting that

from where

Then the field calculated is one half of the field of a conductor charged with , this means that the magnitude of the charged conductor is

Therefore the answer is False.

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.