0
$\begingroup$

Suppose a positive charge is placed near an earthed conductor. Now a true/false statement in my book reads as follows: "On the surface of the conductor at some points, charges are negative and at some other points, charges may be positive, and distributed non-uniformly" This statement was given as True.

Yes, negative charges will be induced and they will be non uniform. But how can the positive charge be induced on an earthed conductor? Since the conductor is earthed, doesn't it have to maintain charge neutrality but rather just that it's potential needs to be zero? So how can, and why will positive charge be induced on the surface of an earthed conductor? Is there something I am missing?

Improve this question
$\endgroup$
1
  • $\begingroup$ I cannot really reason out why they should not induce. But it's just that I don't feel that they should. In case of a non-earthed conductor, they will since it has to maintain a charge neutrality. But I don't understand why would that happen in this case $\endgroup$
    – marks_404
    Commented Aug 28, 2021 at 13:05

2 Answers 2

Reset to default
2
$\begingroup$

If a positive charge is brought near an “earthed” conductor, it will attract electrons from the earth. There will be no “net” positive charge on any part of the conductor (which initially had no net charge).

Improve this answer
$\endgroup$
2
  • $\begingroup$ Does it then imply that the statement given was false? $\endgroup$
    – marks_404
    Commented Aug 28, 2021 at 15:32
  • $\begingroup$ I think so. If the conductor were not grounded, electrons would be attracted toward the external positive charge, leaving a positive charge behind, but that gets neutralized if electrons can flow from the ground. $\endgroup$
    – R.W. Bird
    Commented Aug 28, 2021 at 18:12
1
$\begingroup$

I guess it depend upon the symmetry of the conductor as well, and when a positively charged conductor is brought near the earthed conductor, then high negative charged density would build up at one end and it will induce electronic repulsion in the conductor, allowing the charge density gradually decrease. Thus it is relative phenomenon, i.e. farther end is relatively more positive.

Improve this answer
$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.