**Correct Option: A. Electrons in the sphere are repelled, causing a positive charge to accumulate on the side closest to the rod.** ### Detailed Explanation: When a negatively charged rod is brought near a neutral metallic sphere, a phenomenon known as **electrostatic induction** occurs. Here’s a step-by-step breakdown of what happens: 1. **Understanding Charge Distribution**: - A neutral metallic sphere has an equal number of positive charges (protons) and negative charges (electrons). In a neutral state, these charges are evenly distributed throughout the sphere. 2. **Introducing the Negatively Charged Rod**: - When the negatively charged rod approaches the sphere, the electric field created by the rod influences the charges within the sphere. The electric field emanating from the negatively charged rod exerts a force on the electrons in the sphere. 3. **Movement of Electrons**: - Since like charges repel, the electrons in the sphere (which are also negatively charged) are repelled by the negatively charged rod. This repulsion causes the electrons to move away from the side of the sphere that is closest to the rod. 4. **Charge Accumulation**: - As the electrons move away from the side of the sphere nearest to the rod, this side becomes positively charged due to a deficiency of electrons. Conversely, the side of the sphere that is farthest from the rod accumulates excess electrons, becoming negatively charged. 5. **Resulting Charge Distribution**: - The result is that the side of the sphere closest to the rod has a positive charge, while the side farthest from the rod has a negative charge. However, the sphere as a whole remains neutral because the total number of positive and negative charges is still equal. ### Why Other Options Are Incorrect: - **Option B**: "Protons in the sphere are attracted, causing a positive charge to accumulate on the side farthest from the rod." - This option is incorrect because protons are bound within the atomic nucleus and do not move freely within the metallic sphere. The movement of charge in this scenario is due to the mobility of electrons, not protons. - **Option C**: "The sphere remains neutral with no charge distribution change." - This option is misleading. While the sphere remains electrically neutral overall, there is a significant change in charge distribution due to the movement of electrons. The presence of the negatively charged rod induces a separation of charges within the sphere. - **Option D**: "Electrons in the sphere are attracted, causing a negative charge to accumulate on the side closest to the rod." - This option is incorrect because the electrons are repelled by the negatively charged rod, not attracted. The repulsion causes a positive charge to accumulate on the side closest to the rod, not a negative charge. ### Summary of Key Points: - **Electrostatic Induction**: The process where a charged object causes a redistribution of charges in a nearby neutral conductor. - **Movement of Electrons**: In the presence of a negatively charged rod, electrons in the sphere are repelled, leading to a positive charge on the side closest to the rod. - **Charge Distribution**: The sphere becomes polarized, with one side positively charged and the other negatively charged, but remains overall neutral. - **Protons are Stationary**: Protons do not move in response to electric fields; only electrons, which are mobile, contribute to charge redistribution. This understanding of electrostatic induction is crucial for grasping concepts in electrostatics and the behavior of charged objects.