locus of all adjacent points at which the phase of vibration of a physical quantity associated with the wave in the same

locus of all adjacent points at which the electric field is the same

series of points on the wave with the same amplitude

series of points on the wave with the same frequency

Physics - Wave Optics - Quiz-5

In YDSE, two thin transparent films of mica and glass are put in the path of two waves from coherent sources $S_{1} and S_{2}$ . If their thicknesses are 3t and 2t respectively, what should be the refractive index of mica so that central maxima is found at $O (μ_{g l a s s} = 1.5)$ ?

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1.25
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1.5
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1.75
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1.33

In Young's double-slit experiment sources of equal intensities are used. Distance between slits is d and the wavelength of light used is $λ$ ( $λ$ <<d). The angular separation of nearest points on either side of central maximum where intensities become half of the maximum value is

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$\frac{λ}{d}$
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$\frac{λ}{2 d}$
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$\frac{λ}{4 d}$
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$\frac{λ}{6 d}$

The angular width of the principal maximum in Fraunhofer single slit diffraction is 0.1 radian. The angular width of second-order secondary maxima is

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0.05 radian
0%

0.1 radian
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0.5 radian
0%

0.25 radian

In Young's double-slit experiment, the distance between the slits is 1 mm. The wavelength of the light used is 600 nm. Fringe width of the interference pattern (as shown in the figure) is :

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0.6 mm
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0.3 mm
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0.4 mm
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0.2 mm

Four coherent sources of intensity l are superimposed constructively at a point. The intensity at that point is

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4l
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8l
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16l
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24l

In Young's double-slit experiment, the intensities at the points of maxima and minima are $l_{0}$ and zero respectively. Intensities of individual sources are

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$4 l_{0}$
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$\frac{l_{0}}{2}$
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$2 l_{0}$
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$\frac{l_{0}}{4}$

Two coherent light sources $S_{1} and S_{2}$ are kept at equal distances $λ$ from the center of the circle on the same plane of the circle as shown in the figure. In one complete revolution on the circular path, the number of maxima observed is: ( $λ$ = wavelength of light used and 2λ<<R)

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4
0%

6
0%

8
0%

12

The ratio of intensities in consecutive maximas in a diffraction pattern due to a single slit is

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$1 : \frac{4}{9 π^{2}} : \frac{4}{25 π^{2}}$
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$1 : \frac{4}{9} : \frac{4}{25}$
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$1 : \frac{4}{π^{2}} : \frac{9}{π^{2}}$
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1: 4: 9

In an interference pattern, the position of central maxima is 5 mm from a certain point P on the screen. The fringe width is 0.6 mm. The distance of the third minima from point P is

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3.2 mm
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3.3 mm
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3.5 mm
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3.8 mm

In Young's double-slit experiment the separation between the slits is 4 $λ$ ( $λ$ is the wavelength of the light used). The maximum number of maxima formed on the screen placed at a distance of 1 m from the slits, is

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6
0%

7
0%

9
0%

11

In the following question, a statement of assertion (A) is followed by a statement of the reason (R)

A: Light of different colours travel at different speeds in a vacuum.

R: Speed of light depends on mechanical properties of the medium.

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If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
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If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
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If Assertion is a true statement but Reason is false, then mark (3).
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If both Assertion and Reason are false statements, then mark (4).

If 5th order maxima of wavelength 4000 $\overset{o}{A}$ in Young's double-slit experiment, coincides with $n^{t h}$ order maxima of wavelength 5000 $\overset{o}{A}$ , then n is equal to:

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5
0%

8
0%

4
0%

10

Light of wavelength 6000 $\overset{o}{A}$ in air enters a medium of refractive index 1.5. Frequency and wavelength of light in the medium respectively are

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$5 \times 10^{14} Hz, 6000 \overset{o}{A}$
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$5 \times 10^{14} Hz, 4000 \overset{o}{A}$
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$\frac{10}{3} \times 10^{14} Hz, 4000 \overset{o}{A}$
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$\frac{10}{3} \times 10^{14} Hz, 6000 \overset{o}{A}$

The ratio of angular width of principal maximum to the angular width of the secondary maximum in single slit diffraction is

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4 : 1
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2 : 1
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5 : 1
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3 : 1

The resolving power of a microscope can be increased by using:

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red light.
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blue light.
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oil between objective lens and object.
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both 2 & 3.

Monochromatic light of a wavelength $λ$ in air is refracted into a glass slab of refractive index $μ$ . The wavelength of light in the glass is

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$λ$
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$μ$ $λ$
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$\frac{λ}{μ}$
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$\frac{λ}{μ^{2}}$

Two coherent sources are 0.3 mm apart. They are 1 m away from the screen. The second dark fringe is at a distance of 0.3 cm from the center. The distance of the fourth bright from the centre is

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0.16 cm
0%

1.6 cm
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0.8 cm
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8 cm

Assume that light of wavelength 7000 $\overset{o}{A}$ is coming from a star. The limit of resolution (in radian) of a telescope whose objective has a diameter of 244 cm, will be

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$2.5 \times 10^{- 7}$
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$5.0 \times 10^{- 7}$
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$3.5 \times 10^{- 7}$
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$4.5 \times 10^{- 7}$

Light of wavelength 5000 $\overset{o}{A}$ travelling at a speed of $2 \times 10^{8}$ m/s in medium 1 is incident on a boundary and gets refracted into medium 2. Its wavelength after refraction is found to be 5500 $\overset{o}{A}$ . Which of the following is incorrect?

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Refractive index of medium 2 is $\frac{11}{10}$ .
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On entering medium 2, light bends away from normal.
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Speed of light is more in medium 2 than in medium 1.
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Its frequency remains unchanged.

Yellow light is used in a single slit diffraction pattern with a slit width of 0.5 mm. If the yellow light is replaced by X-rays, then the observed pattern will reveal

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No diffraction pattern
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More narrow central maximum
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More number of fringes
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Less number of fringes

In Young's double hole (slit) experiment using the light of wavelength 6000 $\overset{o}{A}$ , the angular width of the fringe formed on a distant screen is $0.1 °$ . The slit separation is approximate:

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0.34 mm
0%

0.34 cm
0%

0.34 m
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0.034 mm

Intensity at the centre in YDSE is $I_{0}$ . If one of the slits is covered then, the intensity at the centre will be

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$I_{0}$
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2 $I_{0}$
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$I_{0}$ /4
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$I_{0}$ /2

A diffraction pattern is obtained by using a beam of red light. What will happen, if the red light is replaced by blue light?

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Bands will become narrower
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Bands become broader
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No change will take place
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Bands disappear

When a thin transparent plate of thickness t and refractive index $μ$ is placed in the path of one of the two interfering waves of light, then the extra path difference created between two waves due to the plate is

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$(μ + 1) t$
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$(μ - 1) t$
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$(\frac{μ + 1}{t})$
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$μ$ t

If the ratio of amplitudes of two coherent sources producing an interference pattern is 3 : 4, the ratio of intensities at maxima and minima is

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3 : 4
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9 : 16
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49 : 1
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25 : 7

In Young's double-slit experiment, the slit separation is made 3 fold. The fringe width becomes

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$\frac{1}{9}$ times
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$\frac{1}{3}$ times
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9 times
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3 times

Wavefront is:

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locus of all adjacent points at which the phase of vibration of a physical quantity associated with the wave in the same
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locus of all adjacent points at which the electric field is the same
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series of points on the wave with the same amplitude
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series of points on the wave with the same frequency