1. Light is a form of:
A) Matter
B) Energy
C) Force
D) Sound
Answer: B) Energy
2. The speed of light in vacuum is approximately:
A) 3 × 10⁶ m/s
B) 3 × 10⁸ m/s
C) 3 × 10¹⁰ m/s
D) 3 × 10⁴ m/s
Answer: B) 3 × 10⁸ m/s
3. The bending of light when it passes from one medium to another is called:
A) Reflection
B) Refraction
C) Diffraction
D) Dispersion
Answer: B) Refraction
4. The law of reflection states that:
A) Angle of incidence > Angle of reflection
B) Angle of reflection > Angle of incidence
C) Angle of incidence = Angle of reflection
D) Angles are unrelated
Answer: C) Angle of incidence = Angle of reflection
5. A plane mirror forms an image that is:
A) Real and inverted
B) Virtual and erect
C) Real and magnified
D) Virtual and inverted
Answer: B) Virtual and erect
6. The splitting of white light into its component colors is called:
A) Reflection
B) Refraction
C) Dispersion
D) Interference
Answer: C) Dispersion
7. Which color of light has the shortest wavelength?
A) Red
B) Yellow
C) Green
D) Violet
Answer: D) Violet
8. Which color has the longest wavelength in the visible spectrum?
A) Blue
B) Indigo
C) Red
D) Violet
Answer: C) Red
9. The image formed by a concave mirror at its focus is:
A) Virtual and erect
B) Real and inverted
C) Virtual and inverted
D) Same size
Answer: B) Real and inverted
10. A convex mirror always forms an image that is:
A) Real and magnified
B) Virtual and diminished
C) Real and inverted
D) Same size
Answer: B) Virtual and diminished
11. The unit of luminous intensity is:
A) Watt
B) Lux
C) Candela
D) Joule
Answer: C) Candela
12. Light travels fastest in:
A) Water
B) Glass
C) Air
D) Vacuum
Answer: D) Vacuum
13. The phenomenon that explains why the sky appears blue is:
A) Reflection
B) Refraction
C) Scattering
D) Diffusion
Answer: C) Scattering
14. The device used to split white light into spectrum is:
A) Mirror
B) Lens
C) Prism
D) Telescope
Answer: C) Prism
15. The change in direction of light after striking a surface is called:
A) Refraction
B) Reflection
C) Diffusion
D) Absorption
Answer: B) Reflection
16. A real image can be obtained on a:
A) Screen
B) Mirror surface
C) Air
D) Retina only
Answer: A) Screen
17. The index of refraction of a medium depends on:
A) Density of medium
B) Speed of light in medium
C) Both A and B
D) None of these
Answer: C) Both A and B
18. The phenomenon of total internal reflection occurs when light travels from:
A) Rarer to denser medium
B) Denser to rarer medium
C) Vacuum to air
D) Air to vacuum
Answer: B) Denser to rarer medium
19. The critical angle is the angle of incidence for which the angle of refraction is:
A) 0°
B) 45°
C) 90°
D) 180°
Answer: C) 90°
20. Optical fibers work on the principle of:
A) Dispersion
B) Refraction
C) Total internal reflection
D) Interference
Answer: C) Total internal reflection
21. The image formed by a convex lens when the object is beyond 2F is:
A) Real, inverted, diminished
B) Virtual, erect
C) Real, magnified
D) Virtual, inverted
Answer: A) Real, inverted, diminished
22. The power of a lens is measured in:
A) Watt
B) Diopter
C) Lux
D) Meter
Answer: B) Diopter
23. A concave lens always produces:
A) Real image
B) Magnified image
C) Virtual, erect, diminished image
D) Inverted image
Answer: C) Virtual, erect, diminished image
24. The distance between the optical center and the focus is called:
A) Radius
B) Diameter
C) Focal length
D) Aperture
Answer: C) Focal length
25. When light passes through a glass slab, it:
A) Changes frequency
B) Changes speed
C) Changes color
D) Stops
Answer: B) Changes speed
26. The human eye forms image on the:
A) Cornea
B) Iris
C) Retina
D) Lens
Answer: C) Retina
27. A rainbow is formed due to:
A) Reflection only
B) Refraction only
C) Dispersion, refraction and reflection
D) Diffraction
Answer: C) Dispersion, refraction and reflection
28. The phenomenon of bending of light around sharp edges is called:
A) Reflection
B) Refraction
C) Diffraction
D) Polarization
Answer: C) Diffraction
29. The type of mirror used in vehicle side mirrors is:
A) Plane mirror
B) Concave mirror
C) Convex mirror
D) Parabolic mirror
Answer: C) Convex mirror
30. The energy of light depends upon its:
A) Speed
B) Frequency
C) Amplitude only
D) Medium
Answer: B) Frequency