**Correct Option: C. Law of Reflection** ### Explanation of the Correct Answer The Law of Reflection states that when light reflects off a smooth surface, the angle of incidence is equal to the angle of reflection. This can be mathematically expressed as: \[ \theta_i = \theta_r \] Where: - \(\theta_i\) is the angle of incidence (the angle between the incoming light ray and the normal to the surface). - \(\theta_r\) is the angle of reflection (the angle between the reflected light ray and the normal to the surface). **Step-by-Step Explanation:** 1. **Understanding Angles**: - The normal is an imaginary line that is perpendicular to the surface at the point of incidence (where the light strikes the surface). - The angle of incidence is measured from the normal to the incoming ray, while the angle of reflection is measured from the normal to the outgoing ray. 2. **Behavior of Light**: - When light hits a smooth surface (like a mirror), it does not scatter; instead, it reflects in a predictable manner. This predictable behavior is what the Law of Reflection describes. 3. **Practical Example**: - Imagine a flashlight beam hitting a mirror. If the beam strikes the mirror at a 30-degree angle to the normal, it will reflect off the mirror at a 30-degree angle on the other side of the normal. This is a direct application of the Law of Reflection. 4. **Visualizing the Concept**: - If you were to draw this scenario, you would have a straight line representing the incoming light ray, a dashed line representing the normal, and another straight line representing the reflected ray. Both angles (incidence and reflection) would be equal, demonstrating the law visually. ### Explanation of Incorrect Options - **A. Law of Refraction**: - This law describes how light bends when it passes from one medium to another (like from air to water). It is not applicable to reflection, which is the focus of the question. - **B. Law of Conservation of Energy**: - This law states that energy cannot be created or destroyed, only transformed from one form to another. While it is a fundamental principle in physics, it does not specifically address the behavior of light during reflection. - **D. Snell's Law**: - Snell's Law relates to the bending of light as it passes between different media and is expressed as: \[ n_1 \sin(\theta_i) = n_2 \sin(\theta_r) \] where \(n_1\) and \(n_2\) are the refractive indices of the two media. This law is not relevant to the reflection of light, which is what the question is asking about. ### Common Pitfalls - **Confusing Reflection with Refraction**: Students often mix up the concepts of reflection and refraction. Remember, reflection involves bouncing off a surface, while refraction involves bending as light passes through different materials. - **Misunderstanding Angles**: Ensure you always measure angles from the normal line, not from the surface itself. This is a common mistake that can lead to incorrect conclusions. ### Revision Summary - The Law of Reflection states that the angle of incidence equals the angle of reflection (\(\theta_i = \theta_r\)). - Reflection occurs off smooth surfaces, where light behaves predictably. - Snell's Law and the Law of Refraction pertain to light bending, not reflecting. - Always measure angles from the normal line to avoid confusion.