Vision, Optical Devices & Lenses
1. A person who cannot see clearly beyond 10 meters suffers from:
a) Hypermetropia
b) Myopia
c) Cataract
d) Presbyopia
Answer: b
2. Cylindrical lenses are used to correct:
a) Astigmatism
b) Myopia
c) Hypermetropia
d) Presbyopia
Answer: a
3. The power of a camera lens with focal length 5 cm is:
a) +5 D
b) +10 D
c) +15 D
d) +20 D
Answer: d
4. An object placed 5 cm from a concave mirror (f = 15 cm) forms an image that is:
a) Virtual, not magnified
b) Virtual, magnified
c) Real, not magnified
d) Real, magnified
Answer: b
5. A convex lens with a 15 cm focal length has an object placed 10 cm in front of it. The image formed is:
a) Real and magnified
b) Virtual and magnified
c) Virtual and reduced
d) Real and reduced
Answer: b
6. The magnifying power of a simple microscope is given by:
a) D/f
b) 1 + D/f
c) 1 + (D – d)/f
d) 1 + (D + d)/f
Answer: b
7. In a terrestrial telescope, the image is:
a) Always virtual
b) Always inverted
c) Erect, unlike the inverted image in astronomical telescopes
d) Same as astronomical telescopes
Answer: c
Optical Phenomena and Effects
8. Mirage is caused due to:
a) Terrestrial heating and reflection
b) Reflection and diffraction
c) Reflection and refraction
d) Refraction and total internal reflection
Answer: c
9. Optical fibres primarily function to:
a) Reflect light
b) Disperse light
c) Refract light
d) Transmit light
Answer: d
10. The atmosphere-free sky would appear:
a) Blue
b) Red
c) White
d) Black
Answer: d
11. The tower appears larger when approaching due to:
a) Increase in the angle subtended at the eye
b) Increase in focal length of the eye
c) Increase in image size on the retina
d) Both a and c
Answer: d
12. The image formed on the retina persists briefly due to:
a) Retinal after-image effect
b) Persistence of vision (~0.1 s)
Assertion-Reason Answer:
A is true, R is false.
Answer: c
13. A rainbow is formed due to:
a) Refraction and Dispersion
b) Scattering and Refraction
c) Diffraction and Refraction
d) Reflection and Refraction
Answer: a, d
14. The color order in a rainbow (choose incorrect):
a) Violet is the innermost color toward Earth
b) Curvature bends toward Earth
c) Red is outermost toward sky
d) Red is innermost toward Earth
Answer: d
15. When observing a rainbow:
a) We face the Sun and raindrops
b) The Sun is behind us, and we face raindrops
c) In light rain, the Sun is in front
d) The Sun is overhead
Answer: b
16. In dispersion through a prism, the light wave with shortest wavelength:
a) Refracts the most
b) Does not bend
c) Refracts the least
d) Reflects from the prism
Answer: a
Advanced Optical Concepts
17. The phenomenon used in creating 3D images via lasers is called:
a) Optical photography
b) Radiography
c) X-ray photography
d) Holography
Answer: d
18. Light scattering primarily occurs in:
a) Colloidal solutions
b) Acidic solutions
c) Electrolyte solutions
d) Basic solutions
Answer: a
19. The wave with the highest energy among the following is:
a) Blue light
b) Green light
c) Red light
d) Yellow light
Answer: a
20. Number of images formed by two plane mirrors at a 60° angle is:
a) Infinite
b) 7
c) 6
d) 5
Answer: d
21. Optical fibres are mainly used in:
a) Musical instruments
b) Food processing
c) Weaving
d) Communication
Answer: d
22. Which phenomenon proves the transverse nature of light?
a) Reflection
b) Refraction
c) Diffraction
d) Polarization
Answer: d