A positively charged ball is brought close to an electrically neutral isolated conductor. The conductor is then grounded while the ball is kept close. Is the conductor charged positively, charged negatively, or neutral if (a) the ball is first taken away and then the ground connection is removed and (b) the ground connection is first removed and then the ball is taken away?

A positively charged ball is brought close to a neutral isolated conductor, and then the conductor is grounded while the ball is kept close.

If a charged body is made to come close to an uncharged body, then the uncharged body will acquire charges opposite to the polarity of the charged one due to induction. In a grounded connection, the charges on a body constantly flow from the charged one to the ground to obtain the desired neutral charge condition of the body.

Initially, a neutral conductor is brought close to the positively charged conductor; thus, by induction, the charges will induce at the neutral conductor. Since, a positively charged body is brought near, the induced charge on the neutral conductor will be negative.

Now, if the ball is first taken away and then the ground connection is removed, then the conductor becomes neutral as there will be no charge left when the ball is taken away.

Hence, it will be neutral.

From the above part discussion, we get that the neutral conductor is now negatively charged due to the induction charging process.

Now, if the ground connection is first removed and then the ball is taken away, the conductor becomes negatively charged as all the positive charges will be neutralized by grounding.