Explanation:
Let’s go through each question one by one.
1.
Rear-view mirrors in vehicles
Rear-view mirrors need to give a wide field of view so drivers can see more behind them. Convex mirrors bulge outward and spread light, giving a wider view (though objects appear smaller). That’s why cars use
convex mirrors for side/rear-view mirrors.
✔ Correct answer:
b. convex mirrors
2.
Angle of incidence = 30° → angle of reflection?
The law of reflection says: *angle of incidence = angle of reflection*, measured from the normal (perpendicular line to the surface). So if incident angle is 30°, reflected angle is also
30°.
✔ Correct answer:
c. 30⁰
3.
ENT doctors use…
ENT (Ear, Nose, Throat) doctors often use small mirrors to look into body cavities like the throat. They use
concave mirrors because they can focus light onto a small area — helpful for illumination and magnification.
✔ Correct answer:
a. concave mirrors
4.
Rainbow formation is an example of…
A rainbow forms when sunlight enters raindrops, bends (refracts), reflects inside the drop, and then refracts again as it exits — separating white light into colors. This separation of colors is called
dispersion, which happens due to refraction depending on wavelength.
✔ Correct answer:
d. dispersion
5.
Picture shows parallel rays hitting a rough surface and scattering in different directions
The diagram (with many uneven reflected rays) represents
irregular reflection (also called diffuse reflection), which happens on rough surfaces (like paper or walls), unlike regular reflection on smooth surfaces (like mirrors).
✔ Correct answer:
c. irregular reflection
Now Part II: Match the following
6.
Snell’s law → relates angles and refractive indices during refraction → matches
e. Refraction
7.
Speed of light in vacuum → standard value is
3 × 10⁸ m/s → matches
c
8.
Real image → formed when light rays actually converge; it’s
inverted (upside down) → matches
a. Inverted
9.
Virtual image → cannot be projected; appears upright; formed by diverging rays — often described as “erect” → matches
b. Erect
10.
Refractive index of water → known value is about
1.33 → matches
d. 1.33
Double-checking:
- 6 → e
- 7 → c
- 8 → a
- 9 → b
- 10 → d
All match correctly.
Final Answer:
1. b
2. c
3. a
4. d
5. c
6. e
7. c
8. a
9. b
10. d
Parent Tip: Review the logic above to help your child master the concept of worksheet for 8th grade science.
