Q146 / 150 · MHT CET 2026 (20 April Shift 2) · Physics
In diffraction experiment from single slit, the angular width of the central maxima does NOT depend upon
- Awidth of the slit
- Bwavelength of light used.
- Cratio of wavelength and slit width.
- Correct answerDdistance of the slit from the screen.
Solution
In a single slit diffraction experiment, the angular position of the first minimum on either side of the central maximum is given by $\sin \theta = \dfrac{\lambda}{a}$, where $\lambda$ is the wavelength of light and $a$ is the width of the slit.
For small angles, $\theta \approx \dfrac{\lambda}{a}$.
The angular width of the central maximum is $2\theta = \dfrac{2\lambda}{a}$.
This expression shows that the angular width depends on the wavelength of light used, the width of the slit, and their ratio.
It is independent of the distance of the slit from the screen ($D$).
Answer: distance of the slit from the screen.
For small angles, $\theta \approx \dfrac{\lambda}{a}$.
The angular width of the central maximum is $2\theta = \dfrac{2\lambda}{a}$.
This expression shows that the angular width depends on the wavelength of light used, the width of the slit, and their ratio.
It is independent of the distance of the slit from the screen ($D$).
Answer: distance of the slit from the screen.
Hence, the correct answer is option: 'D'.