Question 1: Palette 1/40

NEET 2026 MCQ

In Young's double slit experiment, using monochromatic light of wavelength $\lambda$, the intensity of light at a point on the screen where the path difference is $\lambda$, is $K$ units. The intensity of light at a point where the path difference is $\frac{\lambda}{3}$ will be

A

$\frac{K}{4}$

B

K

C

$2 K$

D

$\frac{K}{2}$

Question 2: Palette 2/40

NEET 2026 MCQ

In interference and diffraction, the light energy is redistributed. If it reduces in one region, producing a dark fringe, it increases in another region, producing a bright fringe.

A. As there is no gain or loss of energy, these phenomena are consistent with the principle of conservation of energy.

B. Diffraction and interference are characteristics exhibited only by light waves.

Choose the correct answer from the options given below:

A

$A$ is true and $B$ is also true

B

$A$ is false, but $B$ is true

C

$A$ is true, but $B$ is false

D

Both A and B are false

Question 3: Palette 3/40

NEET 2025 MCQ

The intensity of transmitted light when a polaroid sheet, placed between two crossed polaroids at $22.5^{\circ}$ from the polarization axis of one of the polaroids, is ( $I 0_0$ is the intensity of polarised light after passing through the first polaroid):

A

$\frac{I_0}{8}$

B

$\frac{I_0}{16}$

C

$\frac{I_0}{2}$

D

$\frac{I_0}{4}$

Question 4: Palette 4/40

NEET 2025 MCQ

An unpolarized light beam travelling in air is incident on a medium of refractive index 1.73 at Brewster's angle. Then

A

Both reflected and transmitted light are perfectly polarized with angles of reflection and refraction close to $60^{\circ}$ and $30^{\circ}$, respectively

B

Transmitted light is completely polarized with angle of refraction close to $30^{\circ}$

C

Reflected light is completely polarized and the angle of reflection is close to $60^{\circ}$

D

Reflected light is partially polarized and the angle of reflection is close to $30^{\circ}$

Question 5: Palette 5/40

NEET 2024 MCQ

Two slits in Young's double slit experiment are $1.5 \mathrm{~mm}$ apart and the screen is placed at a distance of $1 \mathrm{~m}$ from the slits. If the wavelength of light used is $600 \times 10^{-9} \mathrm{~m}$ then the fringe separation is

A

$4 \times 10^{-5} \mathrm{~m}$

B

$9 \times 10^{-8} \mathrm{~m}$

C

$4 \times 10^{-7} \mathrm{~m}$

D

$4 \times 10^{-4} \mathrm{~m}$

Question 6: Palette 6/40

NEET 2024 MCQ

Interference pattern can be observed due to superposition of the following waves:

A. $y=a \sin \omega t$

B. $y=a \sin 2 \omega t$

C. $y=a \sin (\omega t-\phi)$

D. $y=a \sin 3 \omega t$

Choose the correct answer from the options given below.

A

B and C

B

B and D

C

A and C

D

A and B

Question 7: Palette 7/40

NEET 2024 MCQ

A beam of unpolarized light of intensity I0 is passed through a polaroid A, then through another polaroid B, oriented at $60^\circ$ and finally through another polaroid C, oriented at 45$^\circ$ relative to B as shown. The intensity of emergent light is:

A

$\frac{I_0}{16}$

B

$\frac{I_0}{4}$

C

$\frac{I_0}{2}$

D

$\frac{I_0}{32}$

Question 8: Palette 8/40

NEET 2024 MCQ

If the monochromatic source in Young's double slit experiment is replaced by white light, then

A

Interference pattern will disappear

B

There will be a central dark fringe surrounded by a few coloured fringes

C

There will be a central bright white fringe surrounded by a few coloured fringes

D

All bright fringes will be of equal width

Question 9: Palette 9/40

NEET 2024 MCQ

An unpolarised light beam strikes a glass surface at Brewster's angle. Then

A

The reflected light will be partially polarised.

B

The refracted light will be completely polarised.

C

Both the reflected and refracted light will be completely polarised.

D

The reflected light will be completely polarised but the refracted light will be partially polarised.

Question 10: Palette 10/40

NEET 2023 MCQ

Which set of colours will come out in air for a situation shown in figure?

A

Yellow, Orange and Red

B

All

C

Orange, Red and Violet

D

Blue, Green and Yellow

Question 11: Palette 11/40

NEET 2023 MCQ

For Young's double slit experiment, two statements are given below :

Statement I : If screen is moved away from the plane of slits, angular separation of the fringes remains constant.

Statement II : If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases.

In the light of the above statements, choose the correct answer from the options given below :

A

Both Statement I and Statement II are false

B

Statement I is true but Statement II is false

C

Statement I is false but Statement II is true

D

Both Statement I and Statement II are true

Question 12: Palette 12/40

NEET 2022 MCQ

If the screen is moved away from the plane of the slits in a Young's double slit experiment, then the :

A

linear separation of the fringes decreases

B

angular separation of the fringes increases

C

angular separation of the fringes decreases

D

linear separation of the fringes increase

Question 13: Palette 13/40

NEET 2022 MCQ

After passing through a polariser a linearly polarised light of intensity I is incident on an analyser making an angle of 30$^\circ$ with that of the polariser. The intensity of light emitted from the analyser will be

A

${{2I} \over 3}$

B

${I \over 2}$

C

${I \over 3}$

D

${{3I} \over 4}$

Question 14: Palette 14/40

NEET 2022 MCQ

In a Young's double slit experiment, a student observes 8 fringes in a certain segment of screen when a monochromatic light of 600 nm wavelength is used. If the wavelength of light is changed to 400 nm, then the number of fringes he would observe in the same region of the screen is

A

6

B

8

C

9

D

12

Question 15: Palette 15/40

NEET 2020 MCQ

Assume that light of wavelength 600 nm is coming from a star. The limit of resolution of telescope whose objective has a diameter of 2 m is :

A

1.83 $ \times $ 10^-7 rad

B

7.32 $ \times $ 10^-7 rad

C

6.00 $ \times $ 10^-7 rad

D

3.66 $ \times $ 10^-7 rad

Question 16: Palette 16/40

NEET 2020 MCQ

In Young's double slit experiment, if the separation between coherent sources is halved and the distance of the screen from the coherent sources is doubled, then the fringe width becomes :

A

half

B

four times

C

one-fourth

D

double

Question 17: Palette 17/40

NEET 2019 MCQ

In a double slit experiment, when light of wavelength 400 nm was used, the angular width of the first minima formed on a screen placed 1m away, was found to be 0.2^o. What will be the angular width of the first minima, ($\mu $_water = 4/3) if the entire experimental apparatus is immersed in water?

A

0.15^o

B

0.05^o

C

0.1^o

D

0.266^o

Question 18: Palette 18/40

NEET 2018 MCQ

In Young’s double slit experiment the separation d between the slits is 2 mm, the wavelength $\lambda $ of the light used is 5896 $\mathop A\limits^0 $ and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20^o. To increase the fringe angular width to 0.21^o (with same $\lambda $ and D) the separation between the slits needs to be changed to

A

1.9 mm

B

1.8 mm

C

2.1 mm

D

1.7 mm

Question 19: Palette 19/40

NEET 2018 MCQ

Unpolarised light is incident from air on a plane surface of a material of refractive index $\mu $. At a particular angle of incidence i, it is found that the reflected and refracted rays are perpendicular to each other. Which of the following options is correct for this situation?

A

Reflected light is polarised with its electric vector parallel to the plane of incidence

B

Reflected light is polarised with its electric vector perpendicular to the plane of incidence

C

$i = {\sin ^{ - 1}}\left( {{1 \over \mu }} \right)$

D

i = tan^-1$\left( {{1 \over \mu }} \right)$

Question 20: Palette 20/40

NEET 2017 MCQ

Young's double slit experiment is first performed in air and then in a medium other than air. It is found that 8^th bright fringe in the medium lies where 5^th dark fringe lies in air. The refractive index of the medium is nearly

A

1.59

B

1.69

C

1.78

D

1.25

Question 21: Palette 21/40

NEET 2017 MCQ

Two polaroids P₁ and P₂ are placed with their axis perpendicular to each other. Unpolarised light $I$₀ is incident on P₁. A third polaroid P₃ is kept in between P₁ and P₂ such that its axis makes an angle 45^o with that of P₁. The intensity of transmitted light through P₂ is

A

${{{I_0}} \over 4}$

B

${{{I_0}} \over 8}$

C

${{{I_0}} \over 16}$

D

${{{I_0}} \over 2}$

Question 22: Palette 22/40

NEET 2017 MCQ

The ratio of resolving powers of an optical microscope for two wavelength $\lambda $₁ = 4000 $\mathop A\limits^ \circ $ and ${\lambda _2}$ = 6000 $\mathop A\limits^ \circ $ is

A

9 : 4

B

3 : 2

C

16 : 81

D

8 : 27

Question 23: Palette 23/40

NEET 2016 MCQ

A linear aperture whose width is 0.02 cm is placed immediately in front of a lens of focal length 60 cm. The aparture is illuminated normally by a parallel beam of wavelength 5 $ \times $ 10^$-$5 cm. The distance of the first dark band of the diffraction pattern from the centre of the screen is

A

0.10 cm

B

0.25 cm

C

0.20 cm

D

0.15 cm

Question 24: Palette 24/40

NEET 2016 MCQ

The interference pattern is obtained with two coherent light sources of intensity ratio n. In the interference pattern, the ratio ${{{I_{max}} - {I_{\min }}} \over {{I_{max}} + {I_{min}}}}$ will be

A

${{\sqrt n } \over {n + 1}}$

B

${{2\sqrt n } \over {n + 1}}$

C

${{\sqrt n } \over {{{\left( {n + 1} \right)}^2}}}$

D

${{2\sqrt n } \over {{{\left( {n + 1} \right)}^2}}}$

Question 25: Palette 25/40

NEET 2016 MCQ

In a diffraction pattern due to a single slit of width $a$, the first minimum is observed at an angle 30^o when light of wavelength 5000 $\mathop A\limits^ \circ $ is incident on the slit. The first secondary maximum is observed at an angle of

A

sin^$-$1$\left( {{1 \over 2}} \right)$

B

${\sin ^{ - 1}}\left( {{3 \over 4}} \right)$

C

${\sin ^{ - 1}}\left( {{1 \over 4}} \right)$

D

${\sin ^{ - 1}}\left( {{2 \over 3}} \right)$

Question 26: Palette 26/40

NEET 2016 MCQ

The intensity at the maximum in a Young's double slit experiment is $I$₀. Distance between two slits is d = 5$\lambda $, where $\lambda $ is the wavelength of light used in the expreriment. What will be the intensity in front of one of the slits on the screen placed at a distance D = 10d ?

A

${3 \over 4}{I_0}$

B

${{{I_0}} \over 2}$

C

I₀

D

${{{I_0}} \over 4}$

Question 27: Palette 27/40

NEET 2015 MCQ

Two slits in Young's experiment have widths in the ratio 1 : 25. The ratio of intensity at the maxima and minima in the interference pattern, ${{{I_{max}}} \over {{I_{min}}}}$ is

A

${{49} \over {121}}$

B

${4 \over 9}$

C

${9 \over 4}$

D

${{121} \over {49}}$

Question 28: Palette 28/40

NEET 2015 MCQ

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

A

$\pi $ radian

B

${\pi \over 8}$ radian

C

${\pi \over 4}$ radian

D

${\pi \over 2}$ radian

Question 29: Palette 29/40

NEET 2015 MCQ

For a parallel beam of monochromatic light of wavelength '$\lambda $' , diffraction is produced by a single slit whose width 'a' is of the order of the wavelength of the light. If 'D' is the distance of the screen from the slit, the wifth of the central maxima will be

A

${{Da} \over \lambda }$

B

${{2Da} \over \lambda }$

C

${{2D\lambda } \over a}$

D

${{D\lambda } \over a}$

Question 30: Palette 30/40

NEET 2015 MCQ

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 single slit pattern ?

A

0.5 mm

B

0.02 mm

C

0.2 mm

D

0.1 mm

Question 31: Palette 31/40

NEET 2014 MCQ

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

A

K

B

K/4

C

K/2

D

zero

Question 32: Palette 32/40

NEET 2014 MCQ

A beam of light of $\lambda = 600$ 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

A

1.2 cm

B

1.2 mm

C

2.4 cm

D

2.4 mm

Question 33: Palette 33/40

NEET 2013 MCQ

The reddish appearance of the sun at sunrise and sunset is due to

A

the scattering of light

B

the polarisation of light

C

the colour of the sun

D

the colour of the sky

Question 34: Palette 34/40

NEET 2013 MCQ

A parallel beam of light of wavelength $\lambda $ is incident normally on a narrow slit. A diffraction pattern formed on a screen placed perpenficular to the direction of the incident beam. At the second minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of slit is

A

2$\pi $

B

3$\pi $

C

4$\pi $

D

$\pi $$\lambda $

Question 35: Palette 35/40

NEET 2013 MCQ

In Young's double slit experiment the distance between the slits and the screen is doubled. The separation between the slits is reduced to half. As a result the fringe width

A

is halved

B

becomes four times

C

remains unchanged

D

is doubled

Question 36: Palette 36/40

NEET 2013 MCQ

In Young's double slit experiment, the slits are 2 mm apart and are illuminated by photons of two wavelengths ${\lambda _1}$ = 12000 $\mathop A\limits^ \circ $ and ${\lambda _2}$ = 10000 $\mathop A\limits^ \circ $. At what minimum distance from the common central bright fringe on the screen 2 m from the slit will a bright fringe from one interference pattern coincide with a bright fringe from the other ?

A

4 mm

B

3 m

C

8 mm

D

6 mm

Question 37: Palette 37/40

NEET 2007 MCQ

The frequency of a light wave in a material is 2 $ \times $ 10¹⁴ Hz and wavelength is 5000 $\mathop A\limits^ \circ $. The refractive index of material will be

A

1.50

B

3.00

C

1.33

D

1.40

Question 38: Palette 38/40

NEET 2005 MCQ

The angular resolution of a 10 cm diameter telescope at a wavelength of 5000 $\mathop A\limits^ \circ $ is of the order of

A

10⁶ rad

B

10^$-$2 rad

C

10^$-$4 rad

D

10^$-$6 rad.

Question 39: Palette 39/40

NEET 2004 MCQ

A telescope has an objective lens of 10 cm diameter and is situated at a distance of one kilometer from two objects. The minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 $\mathop A\limits^ \circ $, is of the order of

A

0.5 m

B

5 m

C

5 mm

D

5 cm

Question 40: Palette 40/40

NEET 2001 MCQ

A ray of light travelling in air have wavelength $\lambda $, frequency n, velocity v and intensity $I$. If this ray enters into water then these parameters are $\lambda $', n', v' and $I$' respectively. Which relation is correct from following ?

A

$\lambda $ = $\lambda $'

B

n = n'

C

v = v'

D

$I$ = $I$'.