Wave Optics · JEE Main previous year questions

2017 2 questions

1. Q422017 · 9 Apr 2017 · Shift 1

   A single slit of width 0.1 mm is illuminated by a parallel beam of light of wavelength $6000\mathring{\mathrm{A}}$ and diffraction bands are observed on a screen 0.5 m from the slit. The distance of the third dark band from the central bright band is :

   1. A.$3\mathrm{mm}$
   2. B.$9\mathrm{mm}$
   3. C.$4.5\mathrm{mm}$
   4. D.$1.5\mathrm{mm}$
   Show answer

   Answer: B

2. Q512017 · 8 Apr 2017 · Shift 1

   A single slit of width b is illuminated by a coherent monochromatic light of wavelength $\lambda$. If the second and fourthminima in the diffraction pattern at a distance 1 m from the slit are at 3 cm and 6 cm respectively from the central maximum, what is the width of the central maximum ? (i.e. distance between first minimum on either side of the central maximum)

   1. A.$1.5\mathrm{cm}$
   2. B.$3.0\mathrm{cm}$
   3. C.$4.5\mathrm{cm}$
   4. D.$6.0\mathrm{cm}$
   Show answer

   Answer: B