COMEDK · Physics · 26. Wave Optics
An EM wave of frequency \(8 \times 10^{10}\text{ Hz}\) falls normally on a rectangular slit of width \(3\text{ cm}\). What is the total angular width of the central maxima?
- A 4 rad
- B 8 rad
- C 0.25 rad
- D 2 rad
Answer & Solution
Correct Answer
(C) 0.25 rad
Step-by-step Solution
Detailed explanation
Wavelength: \(\lambda = \dfrac{c}{\nu} = \dfrac{3 \times 10^8}{8 \times 10^{10}} = 0.375 \times 10^{-2}\) m \(= 0.375\) cm First minimum condition: \(\sin\theta = \dfrac{\lambda}{a} = \dfrac{0.375}{3} = 0.125\) Since 0.125 is small, \(\theta \approx 0.125\) rad Total angular…
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