Question

The aperture of a spherical mirror refers to:

• A. The curvature of the mirror
• B. The focal length of the mirror
• C. The diameter of the reflecting surface
• D. The distance from the mirror to the object

Hint:

Aperture = Diameter of the reflecting surface.
A larger aperture collects more light, leading to a brighter image, but it can also introduce spherical aberration if it is too large.

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
The question asks for the definition of the term "aperture" in the context of spherical mirrors.

Step 2: Key Formula or Approach:
The aperture describes the size of the mirror opening that admits light. Mathematically, for a circular mirror, it is the linear diameter of the reflecting boundary.

Step 3: Detailed Explanation:

• A spherical mirror is a section cut from a hollow sphere.

• The boundary of the reflecting surface of a spherical mirror is usually circular.

• The linear diameter of this circular boundary is called the aperture of the mirror.

• The aperture determines how much light can enter or reflect off the mirror, which directly influences the intensity or brightness of the image formed. A larger aperture collects more light, producing a brighter image.

• In introductory optics, we assume a "small aperture" approximation, which simplifies calculations and allows us to use the relation \(f = R / 2\).


Step 4: Final Answer:
The aperture refers to the diameter of the reflecting surface.