- 1(current)
Q. No.The angular width of the central maximum in the Fraunhofer diffraction for \(\lambda=6000~{\mathring{A}}\) is \(\theta_0.\) When the same slit is illuminated by another monochromatic light, the angular width decreases by \(30\%.\) The wavelength of this light is:
1. \(1800~{\mathring{A}}\)
2. \(4200~{\mathring{A}}\)
3. \(420~{\mathring{A}}\)
4. \(6000~{\mathring{A}}\)
Subtopic: Â Diffraction |
 77%
Level 2: 60%+
NEET - 2019
Hints
A linear aperture whose width is \(0.02\) cm is placed immediately in front of a lens of focal length \(60\) cm. The aperture is illuminated normally by a parallel beam of wavelength \(5\times 10^{-5}\) cm. The distance of the first dark band of the diffraction pattern from the centre of the screen is:
| 1. | \( 0.10 \) cm | 2. | \( 0.25 \) cm |
| 3. | \( 0.20 \) cm | 4. | \( 0.15\) cm |
Subtopic: Â Diffraction |
 72%
Level 2: 60%+
NEET - 2016
Hints
In a diffraction pattern due to a single slit of width \(a\), the first minimum is observed at an angle of \(30^{\circ}\) when the light of wavelength \(5000~\mathring{A}\) is incident on the slit. The first secondary maximum is observed at an angle of:
1. \(\sin^{-1}\frac{2}{3}\)
2. \(\sin^{-1}\frac{1}{2}\)
3. \(\sin^{-1}\frac{3}{4}\)
4. \(\sin^{-1}\frac{1}{4}\)
1. \(\sin^{-1}\frac{2}{3}\)
2. \(\sin^{-1}\frac{1}{2}\)
3. \(\sin^{-1}\frac{3}{4}\)
4. \(\sin^{-1}\frac{1}{4}\)
Subtopic: Â Diffraction |
 70%
Level 2: 60%+
NEET - 2016
Hints
- 1(current)
Q. No.
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