Question

What happens if the glass plate is replaced by a mirror?

Answer 1

If a glass plate is replaced by a mirror in an optical setup, the main change would be the reflection of light. Here's how:

1. Reflection instead of Transmission:
   

   - A glass plate typically allows light to pass through (transmits) with some amount of reflection at the surface.
   - A mirror, on the other hand, reflects most of the light that strikes its surface. It does not let light pass through. This means that if you replace a glass plate with a mirror, light will be reflected rather than transmitted.

1. Change in Path of Light:
   

   - If you're using the glass plate to let light pass through to the other side, replacing it with a mirror would prevent light from passing through and cause it to reflect back.
   - This change can drastically alter the behavior of the light in optical systems, like in telescopes or microscopes, where the purpose is to direct light along a specific path.

1. Angle of Reflection:
   

   - A mirror follows the law of reflection: the angle of incidence (the angle at which light hits the mirror) equals the angle of reflection (the angle at which the light bounces off).
   - In contrast, a glass plate typically does not reflect light in such a predictable way unless it is designed to do so (like a partially reflecting glass plate).

1. Appearance and Visual Effects:
   

   - If you look at the surface of a mirror, it creates a clear reflection of the objects in front of it. Replacing a glass plate with a mirror could change how you see things, creating a reflective image instead of just seeing through the glass.

So, in short, replacing a glass plate with a mirror changes the way light behaves—what was once transmitted through the plate will now be reflected by the mirror.