Light changes its direction when going obliquely from one transparent medium to another transparent medium. This is called the ______ of light. 73
refraction
______ are self luminous and can be seen at night in the absence of sunlight. 76
Stars
1 nm = ______ m. 77
10− 9
______ is a beautiful natural phenomenon which is the combined effect of natural processes like dispersion, refraction and total internal reflection of light. 78
Rainbow