Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
AIIMS 2016
Exam
AIIMS
Year
2016
Subject
Physics
Chapter
Wave Optics

AIIMS 2016 · Physics · Wave Optics

In a Fraunhofer diffraction at single slit of width d with incident...

In a Fraunhofer diffraction at single slit of width dd with incident light of wavelength 5500 A˚Å, the first minimum is observed, at angle 30∘30^{\circ}. The first secondary maximum is observed at an angle θ=\theta=

Options

  1. Asin⁡−112\sin ^{-1} \frac{1}{\sqrt{2}}
  2. Bsin⁡−114\sin ^{-1} \frac{1}{4}
  3. Csin⁡−134\sin ^{-1} \frac{3}{4}
  4. Dsin⁡−132\sin ^{-1} \frac{\sqrt{3}}{2}

Correct answer

C. sin⁡−134\sin ^{-1} \frac{3}{4}

Step-by-step solution

Slit width =d=d λ=5500A˚=5.5×10−7 m,θn=30∘\lambda=5500 Å=5.5 \times 10^{-7} \mathrm{~m}, \theta_n=30^{\circ} For first secondary minima, dsin⁡θn=λd \sin \theta_n=\lambda d=λsin⁡θn=5.5×10−7sin⁡30∘=11×10−7 md=\frac{\lambda}{\sin \theta_n}=\frac{5.5 \times 10^{-7}}{\sin 30^{\circ}}=11 \times 10^{-7} \mathrm{~m} For first secondary maxima, dsin⁡θn=3λ2d \sin \theta_n=\frac{3 \lambda}{2} i. e. sin⁡θn=3λ2d=3×5.5×10−72×11×10−7\sin \theta_n=\frac{3 \lambda}{2 d}=\frac{3 \times 5.5 \times 10^{-7}}{2 \times 11 \times 10^{-7}} sin⁡θn=34\sin \theta_n=\frac{3}{4} or θn=sin⁡−1(3/4)\theta_n=\sin ^{-1}(3 / 4)
Practice Wave Optics on Quantrex Academy →

More from Wave Optics

An unpolarized light beam of intensity I_0 passes through a series of n Polaroids P_1… MHT CET Medical 2026In a single-slit Fraunhofer diffraction experiment, the first secondary minimum is… MHT CET Medical 2026In the Young's double slit experiment, the intensity of light at a point on the screen is… MHT CET Medical 2026Two images are considered "just resolved" according to Rayleigh's criterion when MHT CET Medical 2026In Young's double slit experiment, the slits are 2\ mm apart and are illuminated by… MHT CET Medical 2026In Young's double slit, 18 fringes are observed to be formed in a certain segment of the… MHT CET Medical 2026When the un-polarised light beam is incident from air to glass (n = 1.5) at the… MHT CET Medical 2026In Young's double-slit experiment, the intensity at a point is ((1)/(4)) of the maximum… MHT CET Medical 2026 Full Wave Optics list All NEET PYQs