### Correct Option: D ### Explanation of the Correct Answer When a negatively charged rod is brought near a neutral metal sphere, a phenomenon known as **electrostatic induction** occurs. Here’s a step-by-step breakdown of what happens: 1. **Understanding Charge Distribution**: A neutral metal sphere has an equal number of positive and negative charges, meaning it has no overall charge. The positive charges are due to protons in the atomic nuclei, while the negative charges are due to electrons. 2. **Bringing the Rod Near the Sphere**: 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. As a result, the electrons move away from the side of the sphere that is closest to the rod. 4. **Polarization of the Sphere**: This movement of electrons causes a separation of charge within the sphere. The side of the sphere that is closest to the rod becomes positively charged (due to a deficit of electrons), while the side that is farther away becomes negatively charged (due to an excess of electrons). This creates a **polarized** state in the sphere, where one side is positively charged and the other side is negatively charged. 5. **Final State of the Sphere**: Although the sphere remains overall neutral (the total number of positive and negative charges is still equal), it is now polarized. The positive side is attracted to the negatively charged rod, while the negative side is repelled. ### Why Other Options Are Incorrect - **Option A: The sphere becomes positively charged as electrons are attracted to the rod.** - This option is incorrect because the electrons are not attracted to the rod; they are repelled. The sphere does not gain a net positive charge; instead, it becomes polarized. - **Option B: The sphere becomes negatively charged as electrons are repelled by the rod.** - This option is misleading. While electrons do move away from the rod, the sphere does not become negatively charged overall. Instead, it becomes polarized, with one side becoming positively charged and the other side negatively charged. - **Option C: The sphere remains neutral with no change in charge distribution.** - This option is incorrect because the presence of the negatively charged rod does cause a change in the charge distribution within the sphere. The charges rearrange themselves, leading to polarization. ### Summary of Key Points - **Electrostatic Induction**: The process where a charged object influences the distribution of charges in a nearby neutral object without direct contact. - **Charge Movement**: Electrons in the sphere are repelled by the negatively charged rod, leading to a separation of charge. - **Polarization**: The sphere becomes polarized, with a positive side closer to the rod and a negative side farther away, while remaining overall neutral. - **Overall Neutrality**: The sphere does not gain a net charge; it simply experiences a redistribution of its existing charges. This understanding of electrostatic induction is crucial for grasping concepts in electrostatics and the behavior of charged objects.