Diffraction of Waves

IMPORTANT

Diffraction of Waves: Overview

This topic covers concepts, such as, Diffraction of Light Waves, Diffraction at Single Slit, Diffraction of Sound Waves and Its Importance in Daily Life, Observing Diffraction in a Ripple Tank & Diffraction of Radio Waves and Microwaves etc.

Important Questions on Diffraction of Waves

EASY
IMPORTANT

Light, from a monochromatic source, is made to fall on a single slit of variable width. An experimentalist records the following data for the linear width of the principal maxima on a screen kept at a distance of 1 m from the plane of the slit.
 

S.no 1 2 3 4 5
Width of the slit 0.1 mm 0.2 mm 0.3 mm 0.4 mm 0.5 mm
Linear width of the principal maxima 6 mm 3 mm 1.98 mm 1.52 mm 1.2 mm


Using the observations from this data estimate the value of the wavelength of light used.

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IMPORTANT

In a single slit diffraction experiment, a slit of width ‘d’ is illuminated by red light of wavelength 650 nm. For what value of ‘d’ will

​(i) the first minimum fall at an angle of diffraction of   30° , and

(ii) the first maximum fall at an angle of diffraction of   30° :

EASY
IMPORTANT

In a single slit diffraction experiment, a slit of width d is illuminated by red light of wavelength 650 nm. For what value of d will 

​(i) the first minimum fall at an angle of diffraction of  30° and

(ii) the first maximum fall at an angle of diffraction of   30°

MEDIUM
IMPORTANT

Yellow light is used in a single slit diffraction experiment with slit width of 0.6 mm. If yellow light is replaced by X-rays, then the observed pattern will reveal,

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Consider Fraunhoffer diffraction pattern obtained with a single slit illuminated at normal incidence. At the angular position of the first diffraction minimum, the phase difference (in radians) between the wavelets from the opposite edges of the slit is

EASY
IMPORTANT

Consider Fraunhoffer diffraction pattern obtained with a single slit illuminated at normal incidence. At the angular position of the first diffraction minimum, the phase difference (in radians) between the wavelets from the opposite edges of the slit is

MEDIUM
IMPORTANT

A beam of light of wavelength 600 nm from a distance source falls on a single slit 1 mm wide and a resulting diffraction pattern is observed on a screen 2 m away. The distance between the first dark fringes on either side of central bright fringe is

EASY
IMPORTANT

A slit of width d is placed in front of a lens of focal length 0.5 m and is illuminated normally with light of wavelength 5.89×10-7 m. The first diffraction minima on either side of the central diffraction maximum are separated by 2×10-3 m. The width d of the slit is_________m.

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Explain diffraction of Sound Waves and Its Importance in Daily Life.

HARD
IMPORTANT

Why AM is not found in train?

HARD
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What is major diffraction between diffraction of microwave and radio wave?

HARD
IMPORTANT

Explain significant gap in diffraction of waves.

HARD
IMPORTANT

Explain how can we observe diffraction pattern in ripple tank.

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For a diffraction from a single slit, the intensity of the central point is

MEDIUM
IMPORTANT

Which is the following colourful patterns is due to diffraction of light?

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Light is diffracted at a single slit. Which of the following graphs best represents how the intensity I of the diffracted light varies with the diffraction angle θ?

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A single-slit diffraction pattern is obtained using a beam of red light. What happens if the red light is replaced by blue light?

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Monochromatic light of wavelength 4300 Ao falls on a slit of width a.  In diffraction pattern first maxima deviates through 30°. Magnitude of slit width a is 

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To observe diffraction, we need at least two slits and a light source.

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What is the shape of the pattern observed when light is projected on a wall through a narrow circular slit?