White light passing through a prism splits into seven colours, and that splitting is called dispersion, so this Class 10 sheet opens with the colour band and its name. Red and violet answers, a spectrum, and water droplets for rainbows follow in the key.
Key Takeaways
White light splits into seven colours in a prism (Q1).
Splitting white light is called dispersion (Q2).
Q3 records red as a colour answer.
Section A: Multiple Choice Questions (1 Mark Each)
Choose the correct option for each question.
1.When white light passes through a prism, it splits into
(a) seven colours(b) two colours(c) no colours(d) four colours
2.The splitting of white light into its constituent colours is called
5.The band of colours obtained on a screen after dispersion is called
(a) a spectrum(b) a shadow(c) an image(d) a diffraction pattern
6.A rainbow is formed due to
(a) dispersion of light by water droplets(b) reflection by plane mirrors(c) refraction through lenses(d) scattering of sound
Section B: Short Answer Type Questions (2 Marks Each)
Show all steps clearly.
7.Define dispersion of light.
8.Name the seven colours of the visible spectrum in order.
9.Which colour of light bends the most and which bends the least in a prism?
10.Why is red used for danger signals?
11.What is a spectrum?
12.How is a rainbow formed?
13.Why do different colours deviate by different amounts in a prism?
14.Give two natural phenomena that occur due to the dispersion of light.
Section C: Numericals & Word Problems (3 Marks Each)
Apply the concepts to solve the problems. Show all working.
15.Red light has a wavelength of 700 nm. Convert this wavelength to metres (1 nm = 1 × 10⁻⁹ m).
16.Violet light has a wavelength of 400 nm. Convert this wavelength to metres (1 nm = 1 × 10⁻⁹ m).
17.Light travels at 3 × 10⁸ m/s. Using frequency = speed ÷ wavelength, find the frequency of light with a wavelength of 6 × 10⁻⁷ m.
18.Using f = c ÷ λ with c = 3 × 10⁸ m/s, find the frequency of violet light of wavelength 4 × 10⁻⁷ m.
19.A prism deviates red light by 40° and violet light by 50°. Find the angular dispersion.
20.The angle of a prism is 60° and the angle of minimum deviation for yellow light is 40°. Using μ = sin((A + D) ÷ 2) ÷ sin(A ÷ 2) with sin 50° = 0.77 and sin 30° = 0.5, find the refractive index.
Answer Key
1. a) seven colours
2. a) dispersion
3. a) red
4. a) violet
5. a) a spectrum
6. a) dispersion of light by water droplets
7. Refer to solution guide.
8. Refer to solution guide.
9. Refer to solution guide.
10. Refer to solution guide.
11. Refer to solution guide.
12. Refer to solution guide.
13. Refer to solution guide.
14. Refer to solution guide.
15. Refer to solution guide.
16. Refer to solution guide.
17. Refer to solution guide.
18. Refer to solution guide.
19. Refer to solution guide.
20. Refer to solution guide.
End of Worksheet
People Also Ask
How many colours does a prism split white light into?
Seven, option (a) in this worksheet (Q1).
What is the splitting of white light called?
Dispersion, option (a) in this worksheet (Q2).
What causes a rainbow?
Dispersion of light by water droplets, option (a) in this worksheet (Q6).
Stuck on a similar problem? Clear your next doubt instantly with the Doubt Solver.
Browse more free worksheets for CBSE Grade 10.