Q56.Given below are two statements :
Statement I :
Compound microscope includes condenser lens, the objective lens and the eye piece lens.
Statement II :
Objective lens has a smaller focal length and aperture than the eye piece.
In the light of the above statements, choose the most appropriate answer from the options given below :
(1) Both Statement I and Statement II are correct
(2) Both Statement I and Statement II are incorrect
(3) Statement I is correct but Statement II is incorrect
(4) Statement I is incorrect but Statement II is correct
Both Statement I is correct and Statement II is incorrect. The correct answer is option (3).
Statement Analysis
Statement I (Correct): A compound microscope indeed includes the condenser lens (focuses light onto specimen), objective lens (primary magnification near specimen), and eyepiece lens (further magnifies for viewer). These form the core optical system for high-resolution imaging.
Statement II (Incorrect): The objective lens has a shorter focal length than the eyepiece (correct for high magnification), but it typically has a larger aperture (numerical aperture, NA) than the eyepiece to capture more light from the specimen. Eyepieces have smaller apertures as they view the intermediate image.
Why Other Options Fail
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Option 1: Wrong because Statement II’s aperture claim is false despite focal length accuracy.
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Option 2: Wrong because Statement I accurately lists essential components.
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Option 4: Wrong because Statement I is true, not false.
Introduction to Microscope Statements
Understanding compound microscope condenser objective eyepiece lens focal length aperture relationships is crucial for NEET optics. Statement I correctly identifies core components while Statement II confuses objective’s larger light-gathering aperture with eyepiece’s design.
Component Functions
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Condenser Lens: Concentrates illumination below stage for specimen clarity.
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Objective Lens: Short focal length (~1-20mm), high NA (0.1-1.4) for resolution.
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Eyepiece Lens: Longer focal length (~25-50mm), lower NA (~0.1-0.25) for comfortable viewing.
Common Exam Error
Statement II traps students forgetting objectives’ larger apertures enable higher resolution despite shorter focal lengths. Total magnification = objective × eyepiece (e.g., 40× × 10× = 400×).
Microscopy Applications
Mastering compound microscope condenser objective eyepiece lens distinctions enables cell biology, microbiology research—essential for academic success and lab proficiency.
