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Physics · PYQ NEET UG 2016(1)
हिन्दीIn a diffraction pattern due to a single slit of width \( a \), the first minimum is observed at an angle \( 30^\circ \) when light of wavelength \( 5000\ \text{Å} \) is incident on the slit. The first secondary maximum is observed at an angle of
Correct answer · Option 4
\( \sin^{-1}(\frac{3}{4}) \)
Explanation
First minimum condition: \( a\sin\theta_1 = \lambda \Rightarrow a\sin 30^\circ = 5000\text{ \AA} \Rightarrow a = 10000\text{ \AA} \). First secondary maximum condition: \( a\sin\theta_2 = \frac{3}{2}\lambda \Rightarrow \sin\theta_2 = \frac{3\lambda}{2a} = \frac{3}{4} \). Thus \( \theta_2 = \sin^{-1}(\frac{3}{4}) \).
