
Copy and complete Table 12.2. (You may assume that the speed of radio waves is )
Station
Wavelength /
Frequency /
Radio A (FM)
Radio B (FM)
Radio B (LW)
Radio C (MW)

Important Questions on Waves
A plane's engine emits a note of constant frequency . It is flying away from a stationary observer at a speed of . Calculate:
(a) The observed wavelength of the sound received by the observer

A plane's engine emits a note of constant frequency . It is flying away from a stationary observer at a speed of . Calculate:
(b) Its observed frequency. (Speed of sound in air .)

Add a third column showing the range of frequencies of each type of radiation.

Type of electromagnetic waves | Wavelength range / |
Radio waves | |
Microwaves | |
Infrared | |
Visible |
(red to (violet) |
Ultraviolet | |
- rays | |
- rays |
Study Table and answer the questions.
(a) Which type of radiation has the narrowest range of wavelengths?

Type of electromagnetic waves | Wavelength range / |
Radio waves | |
Microwaves | |
Infrared | |
Visible |
(red to (violet) |
Ultraviolet | |
- rays | |
- rays |
Study Table and answer the questions.
(b) Which has the second narrowest range?

Type of electromagnetic waves | Wavelength range / |
Radio waves | |
Microwaves | |
Infrared | |
Visible |
(red to (violet) |
Ultraviolet | |
- rays | |
- rays |
Study Table and answer the questions.
(c) What is the range of wavelengths of microwaves, in millimetres?

Type of electromagnetic waves | Wavelength range / |
Radio waves | |
Microwaves | |
Infrared | |
Visible |
(red to (violet) |
Ultraviolet | |
- rays | |
- rays |
Study Table and answer the questions.
(d) What is the range of wavelengths of visible light, in nanometres?

Type of electromagnetic waves | Wavelength range / |
Radio waves | |
Microwaves | |
Infrared | |
Visible |
(red to (violet) |
Ultraviolet | |
- rays | |
- rays |
Study Table and answer the questions.
(e) What is the frequency range of visible light?
