A person is placed in a large, hollow, metallic sphere that is insulated from the ground. If a large charge is placed on the sphere, will the person be harmed upon touching the inside of the sphere?

Question

lgbasallote · Answer

i know that the charges are just on the surface of the sphere..so would that be no?

anonymous · Answer

Yep, no, charge will be distributed on the outer surface of mettalic sphere, form faraday cage.

lgbasallote · Answer

by surface does it mean outside the sphere?

lgbasallote · Answer

because i always see it drawn like this |dw:1348786021718:dw| so i imagine the charges to be inside the surface but at the farthest parts

anonymous · Answer

Repulsion among charge forces them to outer surface. Altough it's not that simple

lgbasallote · Answer

inside the sphere*

shane_b · Answer

It doesn't really matter if it's inside or outside the sphere.  

The question is asking whether they can be harmed by touching the sphere.  The sphere will have a uniform charge and it's insulated from ground....the person inside can touch it all they want without being harmed.

shane_b · Answer

Think of it this way: Is there a path to a lower potential created by the person touching the sphere? The answer is no :)

lgbasallote · Answer

wait..i don't get that last comment

lgbasallote · Answer

what do you mean lower potential?

shane_b · Answer

No path relates to 0 potential difference -> no current will flow through the person.

lgbasallote · Answer

i have no idea about this potential difference you're talking about

lgbasallote · Answer

but i think the concept is simple...if there's no potential difference then there will be no current?

shane_b · Answer

Current won't flow if there no difference in potential difference (charge).  

Another example of this is why birds don't get electrocuted when it lands on a high voltage power line.  There's no path from the higher voltage to ground (or any lower potential).