Waves, sound & optics worksheet with answers

Free printable Waves, sound & optics worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
v = ?

Find the speed v of light in flint glass, which has a refractive index of 1.62.

n = 1.62c = 3.00 × 10⁸ m/s
v = m/s
2.Easy
L = 2 m

A string of length 2 m and mass 2 g is stretched with a tension of 40 N. Find the speed v of transverse waves on it.

L = 2 mm = 2 gT = 40 N
v = m/s
3.Medium
P5 × 75 dB

One machine gives a sound level of 75 dB at a certain point. Find the level β at that point when 5 identical machines run at the same time (incoherent sources).

β1 = 75 dBn = 5
β = dB
4.Medium
θc = ?90°flint glass, n1​ = 1.62crown glass, n2​ = 1.50

Light travels in flint glass (n = 1.62) towards a flat boundary with crown glass (n = 1.50). Find the critical angle θc beyond which it is totally reflected.

n1 = 1.62n2 = 1.50
θc = °
5.Hard
θn1​ = 1.46n2​ = 1.44n0​ = 1.00

An optical fibre has a core with n₁ = 1.46 and a cladding with n₂ = 1.44. Find its numerical aperture NA.

n1 = 1.46n2 = 1.44
NA =
6.Hard
λ = 532 nmθ2​ = ?

Light of wavelength 532 nm falls at right angles on a grating with 500 lines per millimetre. Find the angle θ2 of the order-2 maximum.

N = 500 mm⁻¹λ = 532 nmm = 2
θ2 = °

Answer key

  1. 1. v = 1.852 × 10⁸ m/s
  2. 2. v = 200 m/s
  3. 3. β = 81.99 dB
  4. 4. θc = 67.81 °
  5. 5. NA = 0.2408
  6. 6. θ2 = 32.14 °

Full step-by-step solutions: practise this topic on examproblems.com.