Textbook Question 1A.3

[AustinMcBrideDis3L]

Can someone explain what the letter c (the answer) means?

Which of the following happens when the frequency of elec- tromagnetic radiation decreases? Explain your reasoning.
(a) The speed of the radiation decreases.
(b) The wavelength of the radiation decreases.
(c) The extent of the change in the electrical field at a given point decreases.
(d) The energy of the radiation increases.

[Melody Haratian 2J]

The extent of change refers to the wave’s steepness, or slope. It portrays how much a wave changes over time. The steeper, the higher the extent of change. When you reduce the frequency of a wave, you’re increasing its wavelength. Increasing the wavelength decreases the slope of the wave. Thus, you’re decreasing the wave’s extent of change, or it’s steepness when you decrease frequency.

[805377003]

When you increase the wavelength, you decrease the slope of the wave. This means you change the waves extent of change.

[Aayushi Jani 3A]

As frequency and wavelength are inversely proportional, as frequency decreases, wavelength increases. The extent of change refers to the slope of the wave. When the wavelength increases, the slope, or the extent of change, decreases.