Question

Direction of the electric field just outside the surface of a charged conductor is?

Answer 1

Hint: Use properties of conductor to understand what effects will occur on conductor when electric field is making an angle with the surface of conductor and when it is normal to it. when at angle there will be some movement in electrons in the conductor theoretically and when normal then there should not be any movement of free electrons theoretically.

Complete answer:
Conductors are bodies with free electrons whenever an electric field will come in contact with the surface there are two possibilities: one normal to the surface and another making an angle with the surface. When an electric field is normal to the surface it is expected that there is no movement of the free electrons which works in accordance with the properties of the conductor.

When an electric field is making an angle with the surface of the conductor there should be certain movement of electrons in tangential direction but no such movement is observed which proves that electric field is normal to the surface of the conductor.

Let’s understand more about conductors: Conductors are materials containing free electrons moving throughout the body. There are some characteristic properties of conductors in electrostatics listed below.

-Electrostatic field is Zero inside a conductor, reason being, under the presence of an electrostatic field, the free electrons in a conductor move in the opposite direction thereby creating an opposing field inside the conductor. This opposite field results in redistribution of charges in such a way that there is no electric field inside the conductor.

-Electrostatic potential is constant inside a conductor, no presence of electric field inside the conductor as discussed above.

-No net charge exists inside a conductor, charges accumulate on the surface of the conductor, reason being there is no electric field inside the conductor (reason discussed in above point) by using gaussian theorem no charge can exist inside a conductor.

-Field on the surface on the conductor is normal to the surface reason being if the field is parallel to the surface, it will cause a motion in free electrons to move, but such activity was not observed which proved the fact that all the fields coming in contact with the surface of charged conductor will always be normal to the surface.

Note: All the properties listed above about conductors should be remembered by heart since direct questions are asked on this concept in competitive exams and also such concepts are useful for understanding the concept of Gaussian law.