### Correct Option: A. Infinite ### Detailed Explanation: When an object is placed between two parallel plane mirrors, the mirrors reflect the object back and forth between them. This setup creates a series of images of the object, and the number of images formed can be understood through the principles of reflection. 1. **Understanding Reflection**: - When light from the object hits the first mirror, it reflects back towards the object. The object appears to be at a position behind the mirror, creating the first image. - The light that reflects off the first mirror then travels to the second mirror, where it reflects again. This creates a second image of the object. - This process continues indefinitely, with each mirror reflecting the image created by the other mirror. 2. **Image Formation**: - The images are formed at positions that can be calculated based on the distance of the object from the mirrors. Each image appears to be located at a distance equal to the distance of the object from the mirror, but on the opposite side of the mirror. - For example, if the object is placed at a distance \(d\) from the first mirror, the first image will appear at a distance \(d\) behind the first mirror. The second image will appear at a distance \(d\) behind the second mirror, and so on. 3. **Infinite Images**: - Since the mirrors are parallel, the reflections will continue indefinitely. Each time an image is formed, it can be reflected again by the opposite mirror, leading to a new image. This process does not have a limit as long as the mirrors remain parallel and the object is between them. - Therefore, theoretically, an infinite number of images can be formed. ### Why Other Options Are Incorrect: - **Option B: Eight**: This option suggests a finite number of images. However, as explained, the reflections continue indefinitely, so there is no upper limit to the number of images formed. - **Option C: Four**: Similar to option B, this option implies a finite number of images. The nature of parallel mirrors allows for continuous reflections, leading to an infinite series of images. - **Option D: Two**: This option only accounts for the first two images formed by the initial reflections. It fails to recognize the ongoing process of reflection that occurs between the two mirrors. ### Common Pitfalls: - **Misunderstanding Reflection**: Students may think that there is a limit to the number of reflections, but in the case of parallel mirrors, the reflections can continue indefinitely. - **Assuming Finite Distances**: Some may incorrectly assume that the distance between the mirrors or the object limits the number of images, but as long as the mirrors are parallel, the reflections will not stop. ### Revision Summary: - When an object is placed between two parallel mirrors, an infinite number of images are formed due to continuous reflections. - Each image is created by the light reflecting back and forth between the mirrors. - The process of image formation does not have a limit as long as the mirrors remain parallel. - Understanding the principles of reflection is key to solving problems related to mirrors and image formation.