Answer:
When an electroscope is being charged by induction and the charging rod is moved away before the ground is removed from the knob, the following sequence of events occurs:
Initially, the electroscope is neutral, with the leaves hanging neutrally and close together.
A charged object (usually a negatively charged rod) is brought near the electroscope. This causes the electrons in the electroscope to be repelled by the like charge (negative) on the rod. Electrons move away from the knob and into the leaves.
Since electrons move to the leaves, they become negatively charged, while the knob and the rest of the electroscope become positively charged due to the lack of electrons.
At this point, if you move the charged rod away, the electroscope remains charged. The leaves are now separated and carry a net negative charge, while the knob and the rest of the electroscope have a net positive charge. The separation of the leaves indicates the presence of a charge, and this can be used to detect the presence of a charge even after the charging rod is removed.
If you were to ground the knob (touch it with your hand or connect it to a conductor that goes to the ground), the excess electrons would be neutralized, and the electroscope would return to a neutral state with the leaves hanging neutrally and close together.
So, when the charging rod is moved away before the ground is removed from the knob, the electroscope retains its charged state until the knob is grounded or otherwise discharged.
Step-by-step explanation: