Totally reflecting prisms are preferred to mirrors in periscopes because

I. mirror gives multiple images
II. silvering on mirrors is easily damaged
III. mirrors reflect less light than totally reflecting prisms

AyanfeOba.Dudu

1 year ago

I. Mirrors give multiple images
True – Due to imperfections and partial reflections from both the glass surface and the silvered back, mirrors can produce ghost images or faint multiple reflections.

II. Silvering on mirrors is easily damaged
True – The silvered layer on mirrors can scratch or degrade over time, reducing reflectivity and performance.

III. Mirrors reflect less light than totally reflecting prisms
True – Mirrors reflect less efficiently (around 80–90%), especially after wear. In contrast, total internal reflection in prisms can reflect nearly 100% of the light under proper conditions.

Correct Answer: E. I, II, and III
All three statements are valid reasons why totally reflecting prisms are preferred over mirrors in periscopes.

AyanfeOba.Dudu

11 months ago

I. Mirrors give multiple images
✅ True – Due to imperfections and partial reflections from both the glass surface and the silvered back, mirrors can produce ghost images or faint multiple reflections.

II. Silvering on mirrors is easily damaged
✅ True – The silvered layer on mirrors can scratch or degrade over time, reducing reflectivity and performance.

III. Mirrors reflect less light than totally reflecting prisms
✅ True – Mirrors reflect less efficiently (around 80–90%), especially after wear. In contrast, total internal reflection in prisms can reflect nearly 100% of the light under proper conditions.

✅ Correct Answer: E. I, II, and III
All three statements are valid reasons why totally reflecting prisms are preferred over mirrors in periscopes.