Wave Optics: JEE Mains Previous Year Questions (2021-2024) | Physics for JEE Main & Advanced PDF Download

 Page 1


Previous Year Questions (2021-24): 
Wave Optics 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
A monochromatic light of wavelength 6000 Å is incident on the single slit of width 
0.01 mm . If the diffraction pattern is formed at the focus of the convex lens of 
focal length 20 cm , the linear width of the central maximum is : 
(1) 60 mm 
(2) 24 mm 
(3) 120 mm 
(4) 12 mm 
Q2 - 2024 (01 Feb Shift 2) 
A microwave of wavelength 2.0 cm falls normally on a slit of width 4.0 cm . The 
angular spread of the central maxima of the diffraction pattern obtained on a 
screen 1.5 m away from the slit, will be: 
(1) 30
°
 
(2) 15
°
 
(3) 60
°
 
(4) 45
°
 
Q3 - 2024 (01 Feb Shift 2) 
In Young's double slit experiment, monochromatic light of wavelength 5000 Å is 
used. The slits are 1.0 mm apart and screen is placed at 1.0 m away from slits. 
The distance from the centre of the screen where intensity becomes half of the 
maximum intensity for the first time is __ × 10
-6
 m . 
Q4 - 2024 (27 Jan Shift 2) 
When a polaroid sheet is rotated between two crossed polaroids then the 
transmitted light intensity will be maximum for a rotation of : 
Page 2


Previous Year Questions (2021-24): 
Wave Optics 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
A monochromatic light of wavelength 6000 Å is incident on the single slit of width 
0.01 mm . If the diffraction pattern is formed at the focus of the convex lens of 
focal length 20 cm , the linear width of the central maximum is : 
(1) 60 mm 
(2) 24 mm 
(3) 120 mm 
(4) 12 mm 
Q2 - 2024 (01 Feb Shift 2) 
A microwave of wavelength 2.0 cm falls normally on a slit of width 4.0 cm . The 
angular spread of the central maxima of the diffraction pattern obtained on a 
screen 1.5 m away from the slit, will be: 
(1) 30
°
 
(2) 15
°
 
(3) 60
°
 
(4) 45
°
 
Q3 - 2024 (01 Feb Shift 2) 
In Young's double slit experiment, monochromatic light of wavelength 5000 Å is 
used. The slits are 1.0 mm apart and screen is placed at 1.0 m away from slits. 
The distance from the centre of the screen where intensity becomes half of the 
maximum intensity for the first time is __ × 10
-6
 m . 
Q4 - 2024 (27 Jan Shift 2) 
When a polaroid sheet is rotated between two crossed polaroids then the 
transmitted light intensity will be maximum for a rotation of : 
(1) 60
°
 
(2) 30
°
 
(3) 90
°
 
(4) 45
°
 
Q5 - 2024 (27 Jan Shift 2) 
A parallel beam of monochromatic light of wavelength 5000· Å is incident 
normally on a single narrow slit of width 0.001 mm . The light is focused by 
convex lens on screen, placed on its focal plane. The first minima will be formed 
for the angle of diffraction of (degree). 
Q6 - 2024 (29 Jan Shift 1) 
In a double slit experiment shown in figure, when light of wavelength 400 nm is 
used, dark fringe is observed at ?? . If = 0.2 m . the minimum distance between the 
slits ?? 1
 and ?? 2
 is mm . 
 
Q7 - 2024 (29 Jan Shift 2) 
In Young's double slit experiment, light from two identical sources are 
superimposing on a screen. The path difference between the two lights reaching 
at a point on the screen is 
7?? 4
. The ratio of intensity of fringe at this point with 
respect to the maximum intensity of the fringe is : 
(1) 1/2 
Page 3


Previous Year Questions (2021-24): 
Wave Optics 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
A monochromatic light of wavelength 6000 Å is incident on the single slit of width 
0.01 mm . If the diffraction pattern is formed at the focus of the convex lens of 
focal length 20 cm , the linear width of the central maximum is : 
(1) 60 mm 
(2) 24 mm 
(3) 120 mm 
(4) 12 mm 
Q2 - 2024 (01 Feb Shift 2) 
A microwave of wavelength 2.0 cm falls normally on a slit of width 4.0 cm . The 
angular spread of the central maxima of the diffraction pattern obtained on a 
screen 1.5 m away from the slit, will be: 
(1) 30
°
 
(2) 15
°
 
(3) 60
°
 
(4) 45
°
 
Q3 - 2024 (01 Feb Shift 2) 
In Young's double slit experiment, monochromatic light of wavelength 5000 Å is 
used. The slits are 1.0 mm apart and screen is placed at 1.0 m away from slits. 
The distance from the centre of the screen where intensity becomes half of the 
maximum intensity for the first time is __ × 10
-6
 m . 
Q4 - 2024 (27 Jan Shift 2) 
When a polaroid sheet is rotated between two crossed polaroids then the 
transmitted light intensity will be maximum for a rotation of : 
(1) 60
°
 
(2) 30
°
 
(3) 90
°
 
(4) 45
°
 
Q5 - 2024 (27 Jan Shift 2) 
A parallel beam of monochromatic light of wavelength 5000· Å is incident 
normally on a single narrow slit of width 0.001 mm . The light is focused by 
convex lens on screen, placed on its focal plane. The first minima will be formed 
for the angle of diffraction of (degree). 
Q6 - 2024 (29 Jan Shift 1) 
In a double slit experiment shown in figure, when light of wavelength 400 nm is 
used, dark fringe is observed at ?? . If = 0.2 m . the minimum distance between the 
slits ?? 1
 and ?? 2
 is mm . 
 
Q7 - 2024 (29 Jan Shift 2) 
In Young's double slit experiment, light from two identical sources are 
superimposing on a screen. The path difference between the two lights reaching 
at a point on the screen is 
7?? 4
. The ratio of intensity of fringe at this point with 
respect to the maximum intensity of the fringe is : 
(1) 1/2 
(2) 3/4 
(3) 1/3 
(4) 1/4 
Q8 - 2024 (29 Jan Shift 2) 
In a single slit diffraction pattern, a light of wavelength 6000 Å is used. The 
distance between the first and third minima in the diffraction pattern is found to 
be 3 mm when the screen in placed 50 cm away from slits. The 
width of the slit is __ × 10
-4
 m . 
Q9 - 2024 (30 Jan Shift 1) 
The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of 
width 0.2 mm is focused on the focal plane of a convex lens of focal length 
100 cm . The width of the 1
st 
 secondary maxima will be : 
(1) 2 mm 
(2) 2 cm 
(3) 0.02 mm 
(4) 0.2 mm 
Q10 - 2024 (30 Jan Shift 2) 
A beam of unpolarised light of intensity ?? 0
 is passed through a polaroid ?? and 
then through another polaroid ?? which is oriented so that its principal plane 
makes an angle of 45
°
 relative to that of A. The intensity of emergent light is : 
(1) I
0
/4 
(2) I
0
 
(3) ?? 0
/2 
(4) ?? 0
/8 
Q11 - 2024 (31 Jan Shift 1) 
Two waves of intensity ratio 1:9 cross each other at a point. The resultant 
intensities at the point, when (a) 
Waves are incoherent is I
1
( b) Waves are coherent is ?? 2
 and differ in phase by 
60
°
. If 
?? 1
?? 2
=
10
?? then x = 
Page 4


Previous Year Questions (2021-24): 
Wave Optics 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
A monochromatic light of wavelength 6000 Å is incident on the single slit of width 
0.01 mm . If the diffraction pattern is formed at the focus of the convex lens of 
focal length 20 cm , the linear width of the central maximum is : 
(1) 60 mm 
(2) 24 mm 
(3) 120 mm 
(4) 12 mm 
Q2 - 2024 (01 Feb Shift 2) 
A microwave of wavelength 2.0 cm falls normally on a slit of width 4.0 cm . The 
angular spread of the central maxima of the diffraction pattern obtained on a 
screen 1.5 m away from the slit, will be: 
(1) 30
°
 
(2) 15
°
 
(3) 60
°
 
(4) 45
°
 
Q3 - 2024 (01 Feb Shift 2) 
In Young's double slit experiment, monochromatic light of wavelength 5000 Å is 
used. The slits are 1.0 mm apart and screen is placed at 1.0 m away from slits. 
The distance from the centre of the screen where intensity becomes half of the 
maximum intensity for the first time is __ × 10
-6
 m . 
Q4 - 2024 (27 Jan Shift 2) 
When a polaroid sheet is rotated between two crossed polaroids then the 
transmitted light intensity will be maximum for a rotation of : 
(1) 60
°
 
(2) 30
°
 
(3) 90
°
 
(4) 45
°
 
Q5 - 2024 (27 Jan Shift 2) 
A parallel beam of monochromatic light of wavelength 5000· Å is incident 
normally on a single narrow slit of width 0.001 mm . The light is focused by 
convex lens on screen, placed on its focal plane. The first minima will be formed 
for the angle of diffraction of (degree). 
Q6 - 2024 (29 Jan Shift 1) 
In a double slit experiment shown in figure, when light of wavelength 400 nm is 
used, dark fringe is observed at ?? . If = 0.2 m . the minimum distance between the 
slits ?? 1
 and ?? 2
 is mm . 
 
Q7 - 2024 (29 Jan Shift 2) 
In Young's double slit experiment, light from two identical sources are 
superimposing on a screen. The path difference between the two lights reaching 
at a point on the screen is 
7?? 4
. The ratio of intensity of fringe at this point with 
respect to the maximum intensity of the fringe is : 
(1) 1/2 
(2) 3/4 
(3) 1/3 
(4) 1/4 
Q8 - 2024 (29 Jan Shift 2) 
In a single slit diffraction pattern, a light of wavelength 6000 Å is used. The 
distance between the first and third minima in the diffraction pattern is found to 
be 3 mm when the screen in placed 50 cm away from slits. The 
width of the slit is __ × 10
-4
 m . 
Q9 - 2024 (30 Jan Shift 1) 
The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of 
width 0.2 mm is focused on the focal plane of a convex lens of focal length 
100 cm . The width of the 1
st 
 secondary maxima will be : 
(1) 2 mm 
(2) 2 cm 
(3) 0.02 mm 
(4) 0.2 mm 
Q10 - 2024 (30 Jan Shift 2) 
A beam of unpolarised light of intensity ?? 0
 is passed through a polaroid ?? and 
then through another polaroid ?? which is oriented so that its principal plane 
makes an angle of 45
°
 relative to that of A. The intensity of emergent light is : 
(1) I
0
/4 
(2) I
0
 
(3) ?? 0
/2 
(4) ?? 0
/8 
Q11 - 2024 (31 Jan Shift 1) 
Two waves of intensity ratio 1:9 cross each other at a point. The resultant 
intensities at the point, when (a) 
Waves are incoherent is I
1
( b) Waves are coherent is ?? 2
 and differ in phase by 
60
°
. If 
?? 1
?? 2
=
10
?? then x = 
Q12 - 2024 (31 Jan Shift 2) 
When unpolarized light is incident at an angle of 60
°
 on a transparent medium 
from air. The reflected ray is completely polarized. The angle of refraction in the 
medium is 
(1) 30
°
 
(2) 60
°
 
(3) 90
°
 
(4) 45
0
 
Answer Key 
 
Q1 (2) Q2 (3) Q3 (125) ???? ( 4) 
Q5 (30) Q6 (0.2) Q7 (1) ???? ( 2) 
Q9 (1) Q10(1) Q11 (13) Q12 (1) 
 
Solutions 
Q1 
Linear width 
W =
2?? d
a
=
2 × 6 × 10
-7
× 0.2
1 × 10
-5
 = 2.4 × 10
-2
= 24 mm
 
Q2 
For first minima a sin ?? = ?? 
sin ?? =
?? a
=
1
2
 
?? = 30
°
 
Angular spread = 60
°
 
Q3 
Page 5


Previous Year Questions (2021-24): 
Wave Optics 
2024 
 
Q1 - 2024 (01 Feb Shift 1) 
A monochromatic light of wavelength 6000 Å is incident on the single slit of width 
0.01 mm . If the diffraction pattern is formed at the focus of the convex lens of 
focal length 20 cm , the linear width of the central maximum is : 
(1) 60 mm 
(2) 24 mm 
(3) 120 mm 
(4) 12 mm 
Q2 - 2024 (01 Feb Shift 2) 
A microwave of wavelength 2.0 cm falls normally on a slit of width 4.0 cm . The 
angular spread of the central maxima of the diffraction pattern obtained on a 
screen 1.5 m away from the slit, will be: 
(1) 30
°
 
(2) 15
°
 
(3) 60
°
 
(4) 45
°
 
Q3 - 2024 (01 Feb Shift 2) 
In Young's double slit experiment, monochromatic light of wavelength 5000 Å is 
used. The slits are 1.0 mm apart and screen is placed at 1.0 m away from slits. 
The distance from the centre of the screen where intensity becomes half of the 
maximum intensity for the first time is __ × 10
-6
 m . 
Q4 - 2024 (27 Jan Shift 2) 
When a polaroid sheet is rotated between two crossed polaroids then the 
transmitted light intensity will be maximum for a rotation of : 
(1) 60
°
 
(2) 30
°
 
(3) 90
°
 
(4) 45
°
 
Q5 - 2024 (27 Jan Shift 2) 
A parallel beam of monochromatic light of wavelength 5000· Å is incident 
normally on a single narrow slit of width 0.001 mm . The light is focused by 
convex lens on screen, placed on its focal plane. The first minima will be formed 
for the angle of diffraction of (degree). 
Q6 - 2024 (29 Jan Shift 1) 
In a double slit experiment shown in figure, when light of wavelength 400 nm is 
used, dark fringe is observed at ?? . If = 0.2 m . the minimum distance between the 
slits ?? 1
 and ?? 2
 is mm . 
 
Q7 - 2024 (29 Jan Shift 2) 
In Young's double slit experiment, light from two identical sources are 
superimposing on a screen. The path difference between the two lights reaching 
at a point on the screen is 
7?? 4
. The ratio of intensity of fringe at this point with 
respect to the maximum intensity of the fringe is : 
(1) 1/2 
(2) 3/4 
(3) 1/3 
(4) 1/4 
Q8 - 2024 (29 Jan Shift 2) 
In a single slit diffraction pattern, a light of wavelength 6000 Å is used. The 
distance between the first and third minima in the diffraction pattern is found to 
be 3 mm when the screen in placed 50 cm away from slits. The 
width of the slit is __ × 10
-4
 m . 
Q9 - 2024 (30 Jan Shift 1) 
The diffraction pattern of a light of wavelength 400 nm diffracting from a slit of 
width 0.2 mm is focused on the focal plane of a convex lens of focal length 
100 cm . The width of the 1
st 
 secondary maxima will be : 
(1) 2 mm 
(2) 2 cm 
(3) 0.02 mm 
(4) 0.2 mm 
Q10 - 2024 (30 Jan Shift 2) 
A beam of unpolarised light of intensity ?? 0
 is passed through a polaroid ?? and 
then through another polaroid ?? which is oriented so that its principal plane 
makes an angle of 45
°
 relative to that of A. The intensity of emergent light is : 
(1) I
0
/4 
(2) I
0
 
(3) ?? 0
/2 
(4) ?? 0
/8 
Q11 - 2024 (31 Jan Shift 1) 
Two waves of intensity ratio 1:9 cross each other at a point. The resultant 
intensities at the point, when (a) 
Waves are incoherent is I
1
( b) Waves are coherent is ?? 2
 and differ in phase by 
60
°
. If 
?? 1
?? 2
=
10
?? then x = 
Q12 - 2024 (31 Jan Shift 2) 
When unpolarized light is incident at an angle of 60
°
 on a transparent medium 
from air. The reflected ray is completely polarized. The angle of refraction in the 
medium is 
(1) 30
°
 
(2) 60
°
 
(3) 90
°
 
(4) 45
0
 
Answer Key 
 
Q1 (2) Q2 (3) Q3 (125) ???? ( 4) 
Q5 (30) Q6 (0.2) Q7 (1) ???? ( 2) 
Q9 (1) Q10(1) Q11 (13) Q12 (1) 
 
Solutions 
Q1 
Linear width 
W =
2?? d
a
=
2 × 6 × 10
-7
× 0.2
1 × 10
-5
 = 2.4 × 10
-2
= 24 mm
 
Q2 
For first minima a sin ?? = ?? 
sin ?? =
?? a
=
1
2
 
?? = 30
°
 
Angular spread = 60
°
 
Q3 
Let intensity of light on screen due to each slit is I
0
 
So internity at centre of screen is 4?? 0
 
Intensity at distance y from centre- 
I = I
0
+ I
0
+ 2vI
0
I
0
cos ?? 
I
max
= 4I
0
 
I
max 
2
= 2I
0
= 2I
0
+ 2I
0
cos ?? 
cos ?? = 0 
?? =
?? 2
 
K?x =
?? 2
 
2?? ?? dsin ?? =
?? 2
 
2
?? d ×
y
D
=
1
2
 
y =
?? D
4 d
=
5 × 10
-7
× 1
4 × 10
-3
 
= 125× 10
-6
 
= 125 
Q4 
Let ?? 0
 be intensity of unpolarised light incident on first polaroid. 
?? 1
= Intensity of light transmitted from 1
st 
 polaroid 
=
I
0
2
 
?? be the angle between 1
st 
 and 2
nd 
 polaroid 
?? be the angle between 2
nd 
 and 3
rd 
 polaroid 
?? + ?? = 90
°
( as 1
st 
 and 3
rd 
 polaroid are crossed) 
?? = 90
°
- ??