### Correct Option: A. 30 degrees ### Detailed Explanation: 1. **Understanding Reflection**: - When light strikes a reflective surface, it bounces off the surface. This phenomenon is known as reflection. The behavior of light during reflection is governed by the law of reflection. 2. **Law of Reflection**: - The law of reflection states that the angle of incidence is equal to the angle of reflection. This means that if a ray of light hits a surface at a certain angle, it will reflect off that surface at the same angle. 3. **Defining Angles**: - The **angle of incidence** is the angle formed between the incoming ray of light and the normal (an imaginary line perpendicular to the surface at the point of incidence). - The **angle of reflection** is the angle formed between the reflected ray and the normal. 4. **Applying the Law**: - In this question, the angle of incidence is given as 30 degrees. According to the law of reflection: \[ \text{Angle of Incidence} = \text{Angle of Reflection} \] - Therefore, if the angle of incidence is 30 degrees, the angle of reflection must also be 30 degrees. 5. **Conclusion**: - Thus, the angle of reflection when the ray of light strikes the reflective surface at an angle of incidence of 30 degrees is also 30 degrees. ### Why Other Options Are Incorrect: - **Option B: 45 degrees**: - This option suggests that the angle of reflection is 45 degrees. However, according to the law of reflection, this is incorrect because the angle of reflection must equal the angle of incidence, which is 30 degrees, not 45 degrees. - **Option C: 60 degrees**: - Similar to option B, this option incorrectly states that the angle of reflection is 60 degrees. Again, the law of reflection dictates that the angle of reflection must match the angle of incidence, which is 30 degrees. - **Option D: 90 degrees**: - This option implies that the angle of reflection is 90 degrees. This is not possible under the law of reflection, as it would mean the light is reflecting straight back along the normal, which does not correspond to the given angle of incidence of 30 degrees. ### Summary of Key Points: - The angle of incidence equals the angle of reflection according to the law of reflection. - For an angle of incidence of 30 degrees, the angle of reflection is also 30 degrees. - Incorrect options (B, C, D) do not adhere to the law of reflection. - Always remember to visualize the normal line when considering angles of incidence and reflection. This understanding of reflection is fundamental in optics and is crucial for solving problems related to light behavior in various contexts.