Air, because it is the least dense material listed, meaning that light can travel through it quicker because there are less particles for it to collide with which would cause it to slow down as it loses energy with each collision
Answer:
We can use optical fibers.
Explanation:
The optical fibers are the optical devices which is based on the total internal reflection.
The optical fiber has two layers, one is called core and the other is called cladding.
The refractive index of core is more than the cladding.
As a ray of light falls on the core at more than the critical angle for that pair of media(core and cladding), it suffers the total internal reflection at the interface.
Length of the cord..........................................................
Answer:
b. speed of a wave
Explanation:
The speed of a wave is defined as the product between the wave's frequency and the wave's wavelength:
where
is the wavelength of the wave
f is the frequency
Therefore, we see that this matches the definition listed in choice B:
b. speed of the wave.
The other options are:
a. number of waves passing a point in a second. --> frequency
c. distance between wave crests. --> wavelength
d. time for one full wave to pass. --> period