Question

which is true of the light waves a and b shown below? a has a higher frequency and a shorter wavelength than b. a has a lower frequency and a longer wavelength than b. a has a higher frequency and a longer wavelength than b. a has a lower frequency and a shorter wavelength than b

Explanation:

Step1: Define wavelength

Wavelength is the distance between two consecutive crests or troughs. Visually, wave A has larger distance between consecutive crests/troughs than wave B, so A has a longer wavelength.

Step2: Define frequency - wavelength relation

Frequency $f$ and wavelength $\lambda$ are related by $v = f\lambda$ (where $v$ is the wave - speed, constant for light in a given medium). Since $v$ is constant, when $\lambda$ is larger, $f$ is smaller. As A has a longer wavelength, A has a lower frequency.

Answer:

A has a lower frequency and a longer wavelength than B.