As we know,

so, let's solve for velocity (v)
Technician A is Correct.
You can see this when he says that conductors have more free electrons than insulators. This statement is True.
While Technician B says that, insulators have the lower resistance than conductors. This statement is False.
It depends what rollercoaster your on
Answer:(b)
Explanation:
Optical fiber works on the principle of total internal reflection . Total internal reflection occurs when the following two conditions are met
(1) When the angle of incidence of light is greater than the critical angle and,
(2) When a ray of light travels from a optically denser medium to optically rarer medium .
We know that light bend away from normal when it travels from denser to rarer medium. If we we choose such an angle that the refraction angle is
then the incident angle is called critical angle.
So, the refractive index of cladding must be must be less than the refractive index of core material.