Lenses, Mirrors, and Optical Devices
1. Which type of mirror always forms a smaller image of an object placed in front of it?
a) Plane mirror
b) Convex mirror
c) Concave mirror
d) Convex lens
Answer: b
2. What type of mirror is used in vehicle headlights?
a) Plane mirror
b) Concave mirror
c) Convex mirror
d) Parabolic mirror
Answer: b
3. What is the primary optical element in a magnifying glass?
a) Plano-concave lens
b) Concave lens
c) Convex lens
d) Cylindrical lens
Answer: c
4. The mirror used by ENT doctors is typically:
a) Concave
b) Convex
c) Plane
d) Plano-convex
Answer: a
5. A lens made of flint glass is typically used for:
a) Light protection
b) Colored containers
c) Lenses and optical devices
d) Ultraviolet filtering
Answer: c
6. The lens used in movie projectors is usually a:
a) Zoom lens
b) Meniscus lens
c) Concave lens
d) Convex lens
Answer: d
Vision and Eye Defects
7. A person unable to see distant objects clearly is suffering from:
a) Presbyopia
b) Hypermetropia
c) Astigmatism
d) Myopia
Answer: d
8. A person who cannot see beyond 10 meters clearly has:
a) Far sight
b) Myopia
c) Cataract
d) Hypermetropia
Answer: b
Reflection, Refraction, and Light Behavior
9. A periscope operates on the principle of:
a) Refraction
b) Total internal reflection
c) Diffraction
d) Reflection
Answer: d
10. Total internal reflection cannot occur when light travels from:
a) Water to glass
b) Glass to water
c) Water to air
d) Glass to air
Answer: a
11. Total internal reflection takes place when light travels:
a) From a rarer to denser medium
b) From a denser to rarer medium at an angle greater than the critical angle
c) From a denser to rarer medium at a small angle
d) From glass to water
Answer: b
12. When a ray of light passes from a rarer to a denser medium, its velocity:
a) Increases
b) Decreases
c) Remains unchanged
d) Depends on wavelength
Answer: b
13. When a light ray is refracted, what happens to its speed?
a) Increases from rarer to denser medium
b) Decreases from denser to rarer medium
c) Decreases from rarer to denser medium
d) Velocity does not depend on medium
Answer: c
Image Formation and Measurements
14. A man stands 1 meter in front of a plane mirror and moves 40 cm closer. What is the new distance between him and his image?
a) 60 cm
b) 1.2 m
c) 1.4 m
d) 2.0 m
Answer: b
15. If a convex lens forms an image 20 cm away, and the object is placed 25 cm away on the opposite side, what is the power of the lens?
a) 1 diopter
b) -9 diopters
c) 9 diopters
d) 2 diopters
Answer: c
Optical Phenomena
16. Why does the ocean appear blue?
a) Due to reflection
b) Due to refraction
c) Due to diffraction
d) Due to scattering of sunlight
Answer: d
17. On a rainy day, thin oil films on water show brilliant colors due to:
a) Scattering
b) Dispersion
c) Interference
d) Polarization
Answer: c
18. A soap bubble shows colors in white light due to:
a) Diffraction
b) Polarization
c) Interference
d) Reflection
Answer: c
19. Light scattering occurs in:
a) Colloidal solutions
b) Acidic solutions
c) Electrolyte solutions
d) Basic solutions
Answer: a
20. Radio telescopes are considered better than optical telescopes because:
a) They detect faint galaxies
b) They work in cloudy conditions
c) They work day and night
d) All of the above
Answer: d
Wave Properties & Polarization
21. The phenomenon that confirms light’s transverse nature is:
a) Reflection
b) Refraction
c) Diffraction
d) Polarization
Answer: d
22. Which of the following waves can be polarized?
a) Sound waves in air
b) Longitudinal waves on a string
c) Transverse waves on a string
d) Light waves
Answer: d