### Correct Option: D ### Detailed Explanation: When a negatively charged rod is brought near a neutral metallic sphere, the charges within the sphere undergo a process known as **electrostatic induction**. Here’s a step-by-step breakdown of what happens: 1. **Understanding Charge Distribution**: - A neutral metallic sphere has an equal number of positive and negative charges. In metals, the negative charges are free electrons that can move easily throughout the material. 2. **Bringing the Rod Near the Sphere**: - When the negatively charged rod approaches the sphere, the electric field created by the rod exerts a force on the free electrons in the sphere. Since like charges repel, the negative charges (electrons) in the sphere are repelled by the negatively charged rod. 3. **Charge Redistribution**: - As the electrons are repelled away from the side of the sphere closest to the rod, they move to the far side of the sphere. This movement causes the side of the sphere nearest to the rod to become positively charged (due to a deficit of electrons), while the far side becomes negatively charged (due to an excess of electrons). 4. **Resulting Charge Distribution**: - The sphere as a whole remains neutral because it still has the same total number of positive and negative charges. However, there is now a separation of charge within the sphere: one side is positively charged, and the other side is negatively charged. 5. **Attraction to the Rod**: - The positively charged side of the sphere is attracted to the negatively charged rod. This attraction occurs because opposite charges attract. Therefore, even though the sphere remains overall neutral, it experiences a net attractive force towards the rod. ### Why Other Options Are Incorrect: - **Option A: The sphere becomes positively charged and attracts the rod.** - This option is misleading. While the sphere does develop a positive charge on one side, it does not become overall positively charged. The sphere remains neutral overall due to the presence of both positive and negative charges. - **Option B: The sphere remains neutral, with no movement of charges.** - This option is incorrect because the presence of the negatively charged rod causes the free electrons in the sphere to move. The charges do rearrange, leading to a separation of charge within the sphere. - **Option C: The sphere becomes negatively charged and repels the rod.** - This option is incorrect because the sphere does not become negatively charged overall. Instead, the electrons are pushed away from the rod, leading to a positive charge on the side closest to the rod. The sphere does not repel the rod; rather, it is attracted to it due to the induced positive charge. ### Summary of Key Points: - **Electrostatic Induction**: The process by which charges within a conductor redistribute in response to an external electric field. - **Charge Movement**: Free electrons in the metallic sphere move away from the negatively charged rod, creating a positive charge on the side nearest to the rod. - **Overall Neutrality**: The sphere remains neutral overall, but has a separation of charge (positive on one side, negative on the other). - **Attraction**: The induced positive charge on the sphere attracts it to the negatively charged rod. This understanding of charge behavior is crucial in electrostatics and helps explain many phenomena in physics related to electric fields and forces.