Question

Difficulty: EasyElectromagnetic Waves and Electromagnetic Spectrum

A radio transmitter emits electromagnetic waves with a frequency of 1.0×108 Hz1.0 \times 10^8\text{ Hz}. Given that the speed of light in a vacuum is c=3.0×108 m s1c = 3.0 \times 10^8\text{ m s}^{-1}, what is the wavelength of the emitted wave?

  1. 3.0 m3.0\text{ m}Answer
  2. B
    3.0×1016 m3.0 \times 10^{16}\text{ m}
  3. C
    0.33 m0.33\text{ m}
  4. D
    3.0×101 m3.0 \times 10^{-1}\text{ m}

Answer

The wavelength of the emitted radio wave is 3.0 m3.0\text{ m}.
According to the wave equation c=fλc = f \lambda, the wavelength is found by dividing the speed of light by frequency: λ=3.0×108 m s11.0×108 Hz=3.0 m\lambda = \frac{3.0 \times 10^8\text{ m s}^{-1}}{1.0 \times 10^8\text{ Hz}} = 3.0\text{ m}.

Step-by-Step Solution

1
Identify the given parameters and fundamental formula
Speed of light c=3.0×108 m s1c = 3.0 \times 10^8\text{ m s}^{-1} and frequency f=1.0×108 Hzf = 1.0 \times 10^8\text{ Hz}. The electromagnetic wave relation is c=fλc = f \lambda.
All electromagnetic waves travel at the speed of light in a vacuum.
2
Rearrange the formula to solve for wavelength
λ=cf\lambda = \frac{c}{f}
Dividing both sides of the wave equation by frequency isolates wavelength.
3
Substitute values into the equation and compute the result
λ=3.0×1081.0×108=3.0 m\lambda = \frac{3.0 \times 10^8}{1.0 \times 10^8} = 3.0\text{ m}
Performing the division yields the correct wavelength.

Key Concept

Relationship between wave speed, frequency, and wavelength for electromagnetic radiation in a vacuum.
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