The diagram at right shows a solid metal trapezoidally-shaped object (it extends
ID: 3163233 • Letter: T
Question
The diagram at right shows a solid metal trapezoidally-shaped object (it extends above and below the plane of the paper, in the z direction); the net charge of the metal object is zero. A point charge q = 4 nC is sitting on the x axis at x = 2 m. That positive point charge will attract negative charges within the metal object toward it, and repel positive charges in the metal object away from it; these positive and negative charges will distribute themselves on the surfaces of the object. (They aren't uniformly distributed on the surfaces, though; the diagram is schematic, and is not meant to show the actual locations of the surface charges.) The conductor is in electrostatic equilibrium. Find the magnitude and direction of the electric field produced by the surface charges of the metal object, at the point P in the xy plane (inside the object) at coordinates (3m, 2m).Explanation / Answer
The electric field inside the object at point P(3m, 2m) is 0.
Explanation: the point P lies on the plane x-y and is inside the object as explicitly mentioned in the question. Now the object is a metallic conductor; which implies there are free electrons inside the object. Even if there arises any electric field due to the external charge it will be eliminated as the free electrons will move under the action of the field to reduce to field to 0.