# GS Exam 1 PS 20 Freq. and Wavelength Question

#### thomasfx10

##### Medical Student
10+ Year Member
7+ Year Member
My question is about the relationship to Wavelength, Velocity and Freq.

It was my impression that they are related via the equation:

Freq = Velocity / Wavelength.

However, according to their answer there is not a relationship. What am I missing? Thanks!

20) Which of the following would you expect to remain constant when light travels from one medium to another and the media differ in their refractive indices?

A) Velocity
B) Frequency
C) Wavelength
D) Intensity

INCORRECT:
Explanation Discuss this question

From the passage, both velocity and wavelength (different colors) change (P2; recall velocity and wavelength are directly proportional, PHY 7.1.2). One should also know that the intensity (= the rate of energy propagation through space, PHY 8.3) of a light ray decreases when it passes through a medium other than air (its velocity decreases in the medium and this leads to an overall loss of energy).

#### kehlsh

##### Medic Commando
7+ Year Member
it's like capacitance where formula is C = Q/V but C doesn't go up as Q increases, rather V just increases along with it to make constant C

C can be on the other hand, changed by C = eA/d formula

in here, the freq NEVER change when the waves go to diff media, just the wavelength and velocity. (only exception is probably dispersion in prism)

#### thomasfx10

##### Medical Student
10+ Year Member
7+ Year Member
Wow ... that is good to know! Thanks