When a ray of light travels from optically denser medium to optically rarer medium its velocity decreases?

When light travels from an optically rarer medium to an optically denser medium, the speed decreases because of change in ______ 

• Wavelength

• Frequency

• Amplitude

• Phase

When light travels from an optically rarer medium to an optically denser medium, the speed decreases because of the change in Wavelength. 

Concept: Introduction of Wave Optics

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