At the first minimum adjacent to the central maximum of a single slit diffraction pattern, the phase difference between the Huygen's wavelet from the edge of the slit and the wavelet from the midpoint of the slit is

Concept Questions :-

Diffraction
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Difficulty Level:

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

1. 1.2cm

2. 1.2mm

3. 2.4cm

4. 2.4mm

Concept Questions :-

Diffraction
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Difficulty Level:

In the Young's double-slit experiment, the intensity of light at a point on the screw (where the path difference is λ ) is K. (λ being the wavelength of light used). The intensity at a point where the path difference is λ /4 will be

(a) K

(b) K/4

(c) K/2

(d) zero

Concept Questions :-

Young Double slit experiment
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Difficulty Level:

In Young’s double slit experiment. the slits are 2 mm apart and are illuminated by photons of two wavelengths , λ1= 12000Å and , λ2= 10000Å. At what minimum distance from the common central bright fringe on the screen 2m from the slit will a bright fringe from one interference pattern coincide with a bright fringe from the other?

(a) 8mm

(b) 6mm

(c) 4 mm

(d) 3mm

Concept Questions :-

Young Double slit experiment
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Difficulty Level:

A parallel beam of fast-moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, then which of the following statements is correct?

(a) Direction pattern is not observed on the screen in the case of electrons

(b) The angular width of the central maximum of the diffraction pattern will increase

(c) The angular width of the central maximum will decrease

(d) The angular width of the central maximum will be unaffected

Concept Questions :-

Superposition principle
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Difficulty Level:

Two coherent sources of light can be obtained by

(1) Two different lamps

(2) Two different lamps but of the same power

(3) Two different lamps of the same power and having the same colour

(4) None of the above

Concept Questions :-

Huygens' principle
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Difficulty Level:

By Huygen's wave theory of light, we cannot explain the phenomenon of

(1) Interference

(2) Diffraction

(3) Photoelectric effect

(4) Polarisation

Concept Questions :-

Huygens' principle
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Difficulty Level:

Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are

(1) 5I and I

(2) 5I and 3I

(3) 9I and I

(4) 9I and 3I

Concept Questions :-

Superposition principle
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Difficulty Level:

If L is the coherence length and c the velocity of light, the coherent time is

(1) cL

(2) $\frac{L}{c}$

(3) $\frac{c}{L}$

(4) $\frac{1}{Lc}$

Concept Questions :-

Wave front
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Difficulty Level:

If the amplitude ratio of two sources producing interference is 3 : 5, the ratio of intensities at maxima and minima is

(1) 25 : 16

(2) 5 : 3

(3) 16 : 1

(4) 25 : 9

Concept Questions :-

Superposition principle