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.

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1.Easy
λ = 2.933 mv = 3.00 × 10⁸ m/sf = ?

A radio wave travels at 3.00 × 10⁸ m/s with a wavelength of 2.933 m. Find its frequency f.

λ = 2.933 mv = 3.00 × 10⁸ m/s
f = MHz
2.Easy
λ = 6 mv = ?f = 0.25 Hz

A water wave has a frequency of 0.25 Hz and a wavelength of 6 m. Find its speed v.

f = 0.25 Hzλ = 6 m
v = m/s
3.Medium
FFdo​ = 60 cmf = 20 cm

An object stands 60 cm in front of a thin converging lens with a focal length of 20 cm. Find the magnification m (negative for an inverted image).

do = 60 cmf = 20 cm
m =
4.Medium
FFdo​ = 20 cmf = −10 cm

An object stands 20 cm in front of a thin diverging lens with a focal length of 10 cm. Find the image distance di. Use the sign convention 1/f = 1/do + 1/di (f < 0 for a diverging lens, di < 0 for a virtual image).

do = 20 cmf = −10 cm
di = cm
5.Hard
λ = ?d = 0.1 mmL = 2.5 m79.13 mm

Two slits 0.1 mm apart are lit with monochromatic light. On a screen 2.5 m away, bright fringe number 5 lies 79.13 mm from the central fringe. Find the wavelength λ.

d = 0.1 mmL = 2.5 my5 = 79.13 mmm = 5
λ = nm
6.Hard
λ = 450 nmθ

A diffraction grating has 800 lines per millimetre. Light of wavelength 450 nm falls on it at right angles. What is the highest order mmax of bright maximum that can be seen?

N = 800 mm⁻¹λ = 450 nm
mmax =

Answer key

  1. 1. f = 102.3 MHz
  2. 2. v = 1.5 m/s
  3. 3. m = −0.5
  4. 4. di = −6.667 cm
  5. 5. λ = 633 nm
  6. 6. mmax = 2

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