Can total inrternal reflection take place,when light travesl from rarer to denser medium?

Total inrternal reflection tkes place

Total interval reflection takes place, when light travels from

What happens to the wavelength of light when it goes from rarer to denser medium?

What is the effect when light enters from a rarer medium to a denser medium? Explain with diagram

A ray of light from a sodium lamp undergoes total internal reflection.The critical angle will be smallest,when it travels from

For a spherical surface,when refraction takes place from a rarer medium (mu_1) to a denser medium (mu_2) , we write -(mu_1)/u + (mu_2)/v = ( mu_2-mu_1)/R where the symbols have their usual meanings. Now suppose that the object is placed in the denser to the rarer medium . Then, rewrite the above equation.