Optical Instruments MCQs for Competitive Exams
Optical Instruments MCQs for Competitive Exams
Class: CBSE Class 12
Subject: Physics
Section: Optics
Topic: Optical Instruments
Based on: CBSE Board & Competitive Examination Pattern (NCERT)
Instructions: These Multiple Choice Questions (MCQs) are designed strictly as per the NCERT syllabus, making them ideal for CBSE Class 12 Board and competitive exam preparation.
1. A simple microscope works on the principle of:
Answer: B
A simple microscope uses a convex lens to produce a magnified virtual image by refraction.
A simple microscope uses a convex lens to produce a magnified virtual image by refraction.
2. Magnifying power of a simple microscope increases when focal length:
Answer: B
Magnifying power M = 1 + D/f. Smaller focal length → greater magnification.
Magnifying power M = 1 + D/f. Smaller focal length → greater magnification.
3. Compound microscope has:
Answer: B
It consists of objective and eyepiece lenses, both convex.
It consists of objective and eyepiece lenses, both convex.
4. Objective lens of microscope has:
Answer: B
Small focal length gives high magnification.
Small focal length gives high magnification.
5. Telescope is used to view:
Answer: B
Astronomical telescopes observe distant celestial bodies.
Astronomical telescopes observe distant celestial bodies.
6. Angular magnification of telescope depends on:
Answer: A
M = fo/fe, where fo = objective focal length.
M = fo/fe, where fo = objective focal length.
7. Eyepiece of telescope has:
Answer: B
Short focal length increases magnification.
Short focal length increases magnification.
8. Image formed by astronomical telescope is:
Answer: B
Final image is inverted in normal adjustment.
Final image is inverted in normal adjustment.
9. Resolving power depends on:
Answer: D
Greater aperture and smaller wavelength improve resolution.
Greater aperture and smaller wavelength improve resolution.
10. Least distance of distinct vision is:
Answer: A
For a normal eye, D = 25 cm.
For a normal eye, D = 25 cm.
11. Magnifying power of compound microscope is product of:
Answer: B
Total magnification = Mo × Me.
Total magnification = Mo × Me.
12. Telescope objective forms image at:
Answer: B
Image forms at focal plane of objective.
Image forms at focal plane of objective.
13. Length of telescope in normal adjustment:
Answer: A
Tube length equals sum of focal lengths.
Tube length equals sum of focal lengths.
14. Prism binoculars use:
Answer: A
Total internal reflection erects image.
Total internal reflection erects image.
15. Power of eyepiece is usually:
Answer: B
Short focal length → high power.
Short focal length → high power.
16. Resolving power of microscope increases with:
Answer: A
Larger aperture captures more light details.
Larger aperture captures more light details.
17. Telescope collects more light when aperture:
Answer: B
Larger objective gathers more light.
Larger objective gathers more light.
18. Simple microscope image is:
Answer: B
Image is virtual, erect, magnified.
Image is virtual, erect, magnified.
19. Telescope used on Earth for viewing land objects:
Answer: B
Terrestrial telescope produces erect image.
Terrestrial telescope produces erect image.
20. Optical instruments mainly use lenses for:
Answer: B
Image formation occurs via refraction through lenses.
Image formation occurs via refraction through lenses.