Answer:
Amplitude
Explanation:
The main change occurs in the speed of light when changed from inside to outside prism. Since we knkw that speed is a product of wavelength and velocity, then ultimately these two factors also change.
Speed=wavelength*frequency
From the above, it is only amplitude which will not be affected since it has no relationship with speed, frequency and wavelength. The period of the wave, T will also be affected since period is reciprocal of frequency.