10. A laser shines through a single slit and a diffraction pattern is seen on a

Question

10. A laser shines through a single slit and a diffraction pattern is seen on a screen. Then a single thing about the experiment is changed, so that the pattern looks similar, but covers a smaller portion on the screen. Before change. After change. Select all answers that could account for the smaller pattern. l) The screen was moved further away from the slit. 2) The wavelength of the laser light was decreased. 3) The slit was changed to a smaller width slit. 4) The laser was moved closer to the slit. A: 2 and 3 B: 1, 2, 3, 4 C: No answer is correct. D: 2, 3, 4 E: some other answer. Explain.

Explanation / Answer

ANSWER: C, No answer is correct

Reason:

for 1) If the screen is moved further away from the slit, then it covers a larger portion( as the distance between screen and slit increases diffraction bands width increases) which is wrong according to our diagram

for 2) dispersion of the diffracted light inversely proportional to waveleght, as wavelength decreases dispersion increases i.e portion elaborated, so wrong option for our case

for 3) dispersion of the diffracted light inversely proportional to width of the slit, as width decreases dispersion increases i.e portion elaborated, so wrong option for our case

for 4) dispersion or dispersive power of the grating or slit is independent of the distance between source and slit.

Hence No answer is correct.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

---

---

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