Diffraction Single Slit - UNSOLVED PRACTICE SET

Q7. What is diffraction of light? Distinguish between Fresnel diffraction and Fraunhofer diffraction.

Q8. In single slit diffraction, why is the central maximum the brightest and widest?

Q9. Explain why the intensity of secondary maxima in single slit diffraction decreases rapidly as we move away from the central maximum.

Q10. A single slit of width 0.1 mm is illuminated by light of wavelength 600 nm. Calculate the angular position of the first minimum.

Q11. Why does a single slit produce a diffraction pattern while a wide aperture does not show noticeable diffraction?

Q12. How does the diffraction pattern change when:

(a) The slit width is decreased?

(b) The wavelength of light is increased?

Q13. Explain Fraunhofer diffraction at a single slit. Derive the condition for minima and show that a sin θ = nλ for the nth minimum.

Q14. With the help of a diagram, explain the intensity distribution in single slit diffraction. Why is the central maximum twice as wide as the secondary maxima?

Q15. Compare the interference pattern in Young's double slit experiment with the diffraction pattern in single slit experiment. Discuss the similarities and differences.

Q16. A single slit of width 0.2 mm is illuminated by monochromatic light of wavelength 500 nm. The diffraction pattern is observed on a screen placed 2 m away.

(a) Calculate the angular position of the first minimum.

(a) Calculate the width of the central maximum on the screen.

(c) Calculate the distance between the first and second minima on the screen.

(d) Calculate the angular position of the first secondary maximum.

Q17. In a single slit diffraction experiment, the width of the central maximum is 4 mm on a screen placed 1.5 m from the slit. The wavelength of light is 600 nm.

(a) Calculate the slit width.

(b) Calculate the angular width of the central maximum.

(c) If the slit width is halved, what will be the new width of the central maximum?

Q18. In your school's physics lab, a student performs a single slit diffraction experiment using a laser (λ = 632.8 nm) and a slit of adjustable width.

(a) With the slit width set to 0.1 mm, calculate the width of the central maximum on a screen 2.5 m away.

(b) The student observes that when the slit width is reduced to 0.05 mm, the diffraction pattern becomes more spread out. Calculate the new width of the central maximum and explain why this happens.

(c) The student then replaces the laser with white light. Describe the diffraction pattern that would be observed and explain why the central maximum appears white while the minima are coloured.

(d) A classmate argues that diffraction and interference are the same phenomenon. Present three key differences between single slit diffraction and double slit interference to correct this misconception.

(e) In India, radio signals from distant stations can be received even when there is no direct line of sight due to diffraction around hills and buildings. Explain why AM radio waves (λ ~ 300 m) diffract more significantly than FM radio waves (λ ~ 3 m) around the same obstacle.