hin-film enhanced reflection: An oil film (n = 1.22) of thickness 900 nm floatin

Question

hin-film enhanced reflection:

An oil film (n = 1.22) of thickness 900 nm floating on water (n = 1.33) is illuminated with white light at normal incidence. What is the dominant color reflected (wavelength in vacuum)?

red (677 nm)

something very different fom any of these

near IR (738 nm)

middle IR (1098 nm)

Blue (450 nm)

orange (599 nm)

green (549 nm)

far IR (1197 nm)

middle IR (900 nm)

red (677 nm)

something very different fom any of these

near IR (738 nm)

middle IR (1098 nm)

Blue (450 nm)

orange (599 nm)

green (549 nm)

far IR (1197 nm)

middle IR (900 nm)

Explanation / Answer

Here we need to find the value of the wavelength

2 * t * n = m * lambda

lambda = 2* 1.22 * 900 nm / m = 2196 nm / m ( here m =0,1,2,3 )

Lambda = 2196 nm / 1 = 2196 nm

Lambda = 2196 nm /2 = 1098 nm =====================ANSWER) Middle IR

Lambda = 2196 nm / 3 = 732 nm

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.