### Correct Option: C. The charges within the sphere redistribute, creating a separation of charge. #### Detailed Explanation: When a negatively charged rod is brought near a neutral metal sphere, the following sequence of events occurs: 1. **Understanding Charge Distribution**: A neutral metal sphere has an equal number of positive and negative charges (protons and electrons). The positive charges are fixed in place within the atomic structure of the metal, while the negative charges (electrons) are free to move. 2. **Induction Process**: The presence of the negatively charged rod creates an electric field around it. This electric field exerts a force on the free electrons in the metal sphere. Since like charges repel, the electrons in the sphere will be repelled away from the side of the sphere that is closest to the negatively charged rod. 3. **Separation of Charges**: 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. This process is known as charge separation or polarization. 4. **Overall Charge of the Sphere**: Despite the separation of charges, the sphere as a whole remains neutral because the total number of positive and negative charges is still equal. However, there is now a distribution of charge within the sphere, with one side being positively charged and the other side being negatively charged. 5. **Conclusion**: The correct answer is C because the presence of the negatively charged rod causes the charges within the neutral sphere to redistribute, leading to a separation of charge without changing the overall neutrality of the sphere. #### Why Other Options Are Incorrect: - **Option A: The sphere becomes positively charged overall.** - This option is incorrect because while one side of the sphere becomes positively charged, the other side becomes negatively charged. The sphere remains neutral overall, as the total charge does not change. - **Option B: The sphere becomes negatively charged overall.** - This option is also incorrect for the same reason as option A. The sphere does not gain or lose any electrons overall; it simply redistributes them. Therefore, it does not become negatively charged. - **Option D: The sphere remains neutral with no effect.** - This option is misleading. While the sphere does remain neutral overall, there is a significant effect: the redistribution of charges within the sphere. Saying there is "no effect" ignores the important process of charge separation that occurs. #### Key Formulas and Concepts: - **Coulomb's Law**: This law describes the force between two charged objects. It is not directly used in this scenario but helps understand the interactions between charges. - **Electric Field (E)**: The electric field created by a charge can be described as: \[ E = \frac{k \cdot |q|}{r^2} \] where \( k \) is Coulomb's constant, \( q \) is the charge, and \( r \) is the distance from the charge. #### Common Pitfalls: - **Confusing Charge Induction with Charge Transfer**: Induction involves the movement of charges within an object without transferring any charge to or from the object. This is different from charging by contact, where electrons are transferred. - **Assuming Overall Charge Changes**: Students may mistakenly think that the sphere becomes charged overall. It is crucial to remember that the total charge remains the same; only the distribution changes. ### Revision Summary: - Bringing a negatively charged rod near a neutral metal sphere causes charge redistribution within the sphere. - Electrons are repelled, leading to one side becoming positively charged and the opposite side negatively charged. - The sphere remains neutral overall, but there is a separation of charge. - Understanding the difference between charge induction and charge transfer is key to mastering this concept.