A : When viewing through a compound microscope, our eyes should be positioned not on the eye piece but a short distance away from it for best viewing.
R : The image of the objective in the eye-piece is known as 'eye-ring' and if we position our eyes on the 'eye-ring' and the area of the pupil of out eye is greater or equal to the area of the eye ring, our eyes will collect all the light refracted by the objective.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements, then mark (4).

Answer

To solve the question, we need to analyze the statements A and R regarding the use of a compound microscope.

### Step 1: Understanding Statement A
Statement A claims that when viewing through a compound microscope, our eyes should be positioned not directly on the eyepiece but at a short distance away for the best viewing experience.

**Explanation**:
When using a compound microscope, the eyepiece is designed to magnify the image produced by the objective lens. However, if the eye is positioned too close to the eyepiece, it may not be able to capture the full image effectively. This is because the light rays coming from the eyepiece diverge, and the eye needs a certain distance to focus properly on the image.

### Step 2: Understanding Statement R
Statement R explains that the image of the objective in the eyepiece is known as the 'eye-ring'. It further states that if we position our eyes on the 'eye-ring' and the area of the pupil of our eye is greater than or equal to the area of the eye-ring, our eyes will collect all the light refracted by the objective.

**Explanation**:
The 'eye-ring' is essentially the image formed by the objective lens as viewed through the eyepiece. For optimal viewing, the pupil of the eye should be aligned with the eye-ring. If the pupil is large enough to cover the eye-ring, the eye will be able to capture all the light that has been refracted by the objective lens, leading to a clearer and brighter image.

### Conclusion
Both statements A and R are correct. Statement A is true because positioning the eye a short distance away from the eyepiece allows for better focus and light collection. Statement R is also true as it explains the importance of the eye-ring and the alignment of the pupil with it for optimal light collection.

### Final Answer:
Both statements A and R are true, and R provides a correct explanation for A.

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