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This is from question 4 here:

The question discusses a hollow conducting cylinder with a charge $\lambda$ per unit area and radius $a$. (It also mentions another surrounding cylinder, but that's not relevant to my question.) It asks for the field for all radius $r$. Now for $r<a$ the answer says there is no field ($E=0$). Now it makes sense to me that since there is no charge inside the hollow cylinder, there will be no field radiating outward, but won't there still be a field inside the cylinder everywhere except the exact center that would drive a test charge toward the center of the cylinder?

The answer seems to me to read that a test charge placed inside the cylinder would not experience any force, but this does not make sense to me. Am I missing something?

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See its true that inside the hollow cyclinder (r less than a) there is NO electric field. If you were to keep a charge qnywhere inside the inner cylinder it wont move. Reason being that is as cylinder ( assumed to be very long then only gauss law applies) the electric field produced by inner cylinder radially inward due to positive surface charge density AND the radially outward electric field produced by outer cylinder cancels. Therefore net electric field becomes zero. Thats what i think.

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No charge in the hollow, another way to think of it is; the charge on each opposite side of the hollow is equal hence, no difference in potential exists and so therefore, no electrical field inside.

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