AP Psychology Practice Test

What does intensity in the context of light or sound waves refer to?

1. Brightness or loudness determined by wave's amplitude

2. The energy conversion process

3. The color dimension of light

4. The size of the pupil opening

The correct answer is: Brightness or loudness determined by wave's amplitude

Intensity in the context of light or sound waves specifically refers to the brightness of light or the loudness of sound, which is determined by the amplitude of the wave. In physical terms, a wave’s amplitude is the height of the wave; a larger amplitude results in greater intensity, leading to brighter light or louder sound. This concept is foundational in understanding sensory perception, as our perception of sound and light intensity is directly linked to the amplitude of the waves we receive. For instance, when you turn up the volume on a speaker, the amplitude of the sound waves increases, which corresponds to a perceived increase in loudness. The other options do not directly relate to the concept of intensity as it pertains to amplitude. For example, energy conversion processes pertain more to the mechanisms of turning one form of energy into another, while the color dimension of light relates to wavelength and frequency, not amplitude. The size of the pupil opening is tied to the amount of light that enters the eye but does not define the intensity of light itself.