EASY

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What is the shape of the fringes observed in interference?

Important Questions on Wave Optics

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

In Young's double-slit experiment, in an interference pattern, the second minimum is observed exactly in front of one slit. The distance between the slits is

d

and the distance between source and screen is

D

. The wavelength of the light source used is

EASY

Physics>Optics>Wave Optics>Interference in Thin Films

The interference pattern is obtained with two coherent light sources of intensity ratio,

n

. In the interference pattern, the ratio,

\frac{I_{\max} - I_{\min}}{I_{\max} + I_{\min}}

will be

HARD

Physics>Optics>Wave Optics>Interference in Thin Films

In a Young's double slit experiment, slits are separated by

0.5 mm

, and the screen is placed

150 cm

away. A beam of light consisting of two wavelengths,

650 nm

and

520 nm

, is used to obtain interference fringes on the screen. The least distance from the common central maximum to the point where the bright fringes due to both the wavelengths coincide is:

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

Using monochromatic light of wavelength $λ$ , an experimentalist sets up the Young's double slit experiment in three ways as shown.
If she observes that $y = β^{'}$ , the wavelength of light used is :

Question Image

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

In a Young's double slit experiment, the slits are placed

0.320 mm

apart. Light of wavelength

λ = 500 nm

is incident on the slits. The total number of bright fringes that are observed in the angular range

- 30^{o} \leq θ \leq 30^{o}

is:

EASY

Physics>Optics>Wave Optics>Interference in Thin Films

Young's double slit experiment is first performed in air and then in a medium other than air. It is found that

8^{t h}

bright fringe in the medium lies where

5^{t h}

dark fringe lies in air. The refractive index of the medium is nearly

HARD

Physics>Optics>Wave Optics>Interference in Thin Films

Electrons accelerated from rest by an electrostatic potential are collimated and sent through a Young's double slit experiment. The fringe width is

ω .

If the accelerating potential is doubled, then the width is now close to:

HARD

Physics>Optics>Wave Optics>Interference in Thin Films

In a Young's double slit experiment

15

fringes are observed on a small portion of the screen when light of wavelength

500 n m

is used. Ten fringes are observed on the same section of the screen when another light source of wavelength

λ

is used. Find the value of

λ

(in

n m

) .

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

In Young's double-slit experiment, using monochromatic light of wavelength

λ,

the intensity of light at a point on the screen where path difference is

λ

K

units. Then, the intensity of light at a point where path difference is

\frac{λ}{3}

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

In a double-slit experiment, the two slits are

1 mm

apart and the screen is placed

1 m

away. A monochromatic light of wavelength

500 nm

is used. What will be the width of each slit for obtaining ten maxima of double-slit within the central maxima of a single-slit pattern?

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

In Young’s double-slit experiment, the distance between the two identical slits is

6.1

times larger than the slit width. Then the number of intensity maxima observed within the central maximum of the single-slit diffraction pattern is :

HARD

Physics>Optics>Wave Optics>Interference in Thin Films

Consider a Young's double slit experiment as shown in figure. What should be the slit separation

d

in terms of wavelength

λ

such that the first minima occurs directly in front of the slit

(S_{1})

HARD

Physics>Optics>Wave Optics>Interference in Thin Films

A light source, which emits two wavelengths

λ_{1} = 400 n m

and

λ_{2} = 600 n m

, is used in a Young's double slit experiment. If recorded fringe widths for

λ_{1}

and

λ_{2}

are

β_{1}

and

β_{2}

and the number of fringes for them within a distance y on one side of the central maximum are

m_{1}

and

m_{2}

, respectively, then

HARD

Physics>Optics>Wave Optics>Interference in Thin Films

In the Young's double slit experiment using a monochromatic light of wavelength

λ

, the path difference ( in terms of an integer

n

) corresponding to any point having half the peak intensity is

EASY

Physics>Optics>Wave Optics>Interference in Thin Films

In a double slit experiment, when light of wavelength

400 n m

was used, the angular width of the first minima formed on a screen placed

1 m

away was found to be

0.2 ° .

What will be the angular width of the first minima, if the entire experimental apparatus is immersed in water?

(μ_{w a t e r} = \frac{4}{3})

HARD

Physics>Optics>Wave Optics>Interference in Thin Films

In a Young’s double slit experiment, the separation between the slits is

0.15 m m

. In the experiment, a source of light of wavelength

589 n m

is used and the interference pattern is observed on a screen kept

1.5 m

away. The separation between the successive bright fringes on the screen is:

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

In a double – slit experiment, at a certain point on the screen the path difference between the two interfering waves is

\frac{1}{8} t h

of a wavelength. The ratio of the intensity of light at that point to that at the center of a bright fringe is:

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

The distance between two coherent sources is

1 mm

. The screen is placed at a distance of

1 m

from the sources. If the distance of the third bright fringe is

1.2 mm

from the central fringe, the wavelength of light used is

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

In a Young's double slit experiment slit separation

0.1 m m,

one observes a bright fringe at angle

\frac{1}{40} r a d

by using light of wavelength

λ_{1} .

When the light of wavelength

λ_{2}

is used a bright fringe is seen at the same angle in the same set up. Given that

λ_{1}

and

λ_{2}

are in visible range

(380 n m t o 740 n m),

their values are:

MEDIUM

Physics>Optics>Wave Optics>Interference in Thin Films

A mixture of Yellow light of wavelength

580 nm

and blue light of wave length

450 nm

is incident normally on an air film of thickness $2.9 \times 10^{-4} \mathrm{~mm}$. The colour of reflected light is

What is the shape of the fringes observed in interference?

Important Questions on Wave Optics

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