Comprehension

In a Young’s double-slit experiment, the two slits behave as coherent sources. When coherent light waves superpose over each other they create an interference pattern of successive bright and dark regions due to constructive and destructive interference.
Two slits 2 mm apart are illuminated by a source of monochromatic light and the interference pattern is observed on a screen 5·0 m away from the slits as shown in the figure.

Question: 1

What property of light does this interference experiment demonstrate?

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Young's double-slit experiment provided the first convincing evidence that light behaves as a wave.

Updated On: Jul 2, 2026

Wave nature of light
Particle nature of light
Transverse nature of light
Both wave nature and transverse nature of light

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The Correct Option is A

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Question: 2

The wavelength of light used in this experiment is:

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Always use \[ \beta=\frac{\lambda D}{d} \] for wavelength calculations in YDSE.

Updated On: Jul 2, 2026

720 nm
590 nm
480 nm
364 nm

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The Correct Option is D

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Question: 3

The fringe width in the interference pattern formed on the screen is:

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Fringe width increases with wavelength and screen distance but decreases with slit separation.

Updated On: Jul 2, 2026

1·2 mm
0·2 mm
4·2 mm
6·8 mm

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The Correct Option is A

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Question: 4

The path difference between the two waves meeting at point P, where there is a minimum in the interference pattern is:

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Dark fringes occur when \[ \Delta=(2n+1)\frac{\lambda}{2}. \]

Updated On: Jul 2, 2026

\(8.1\times10^{-7}\,\text{m}\)
\(7.2\times10^{-7}\,\text{m}\)
\(6.5\times10^{-7}\,\text{m}\)
\(6.0\times10^{-7}\,\text{m}\)

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The Correct Option is A

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Question: 5

When the experiment is performed in a liquid of refractive index greater than 1, then fringe pattern will:

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In a medium of refractive index \(n\), \[ \beta_{\text{medium}} = \frac{\beta_{\text{air}}}{n}. \] Therefore higher refractive index means smaller fringe width.

Updated On: Jul 2, 2026