1 PRACTICE SET Notes | EduRev

: 1 PRACTICE SET Notes | EduRev

 Page 1


 
 
1 
PRACTICE SET 
OPTICS 
CODE- 3006                                        SET-A 
Topics Covered: REFLECTION FROM PLANE & SPHERICAL SURFACE AND REFRACTION 
THROUGH PLANE SURFACE 
INSTRUCTIONS: 
(a) Problems from 1-20  are single correct Objective Problems.  
(b)   Problems from 21-25 are More than one correct Answer Problems. 
(c) Problems from 1-20 carry 4 marks each for correct option and -1 for every wrong attempt. 
(d) Problems from 21-25 carry 5 marks each for correct option and 0 for every wrong attempt. 
  
 Time: 50 mins.            Max. Marks: 105
1.  An object AB of 
length 7.5 cm forms 
an inverted image 
A’B’ at the same 
place, when reflected 
from a concave mirror. A parallel ray from top 
of the object B, is incident on the mirror at the 
point P (not shown in figure). If PB’ = 25cm, 
find the focal length of the mirror.  
(a) 20 cm   (b) 15 cm 
(c) 10 cm   (d) 12.5 cm  
2. An object O is placed 
between a concave 
mirror and a plane 
mirror so that the first 
image in both the mirrors coincide at I. F is the 
focus of concave mirror. What should be the 
position of centre of curvature of concave 
mirror.  
(a) A   (b) B 
(c) C   (d) O  
3. A square slab is held in air. A ray 
of light strikes in the middle of 
face PQ at O
1
 so that it is 
internally reflected to strike again 
at O
1
. Find the angle of 
incidence, ? :  
(a) 30
0
   (b) 45
0
  
(c) 60
0
   (d) 90
0
  
4. A concave mirror of radius of curvature h is 
placed at the bottom of a tank containing a 
liquid of refractive index ? upto a depth d. An 
object P is placed at height h above the bottom 
of the mirror. Outside the liquid, an observer O 
views the object and its image in the mirror. The 
apparent distance between these two will be :  
P
h
d
O
 
(a) zero    (b) 
2h
?
 
(c) 
1
h1
??
?
??
?
??
  (d) 
2h
1 ??
 
5. An object is placed before a spherical mirror at a 
distance u. Its erect image is magnified six 
times. Find the distance between focus and the 
object :  
(a) u/4   (b) u/5 
(c) u/7   (d) u/3 
6. The distance between object and its erect but 
diminished image formed due to a spherical 
mirror is 3 times the distance between image 
and the focus while distance between object and 
focus is 2u. If the image is half in size than the 
object, find the distance of the object from the 
mirror:  
(a) 
3u
2
   (b) 
u
2
 
(c) u   (d) 
3u
4
 
P
Q
R
S
?
O
1
C B O A I
F
A
A’
B
B’
Page 2


 
 
1 
PRACTICE SET 
OPTICS 
CODE- 3006                                        SET-A 
Topics Covered: REFLECTION FROM PLANE & SPHERICAL SURFACE AND REFRACTION 
THROUGH PLANE SURFACE 
INSTRUCTIONS: 
(a) Problems from 1-20  are single correct Objective Problems.  
(b)   Problems from 21-25 are More than one correct Answer Problems. 
(c) Problems from 1-20 carry 4 marks each for correct option and -1 for every wrong attempt. 
(d) Problems from 21-25 carry 5 marks each for correct option and 0 for every wrong attempt. 
  
 Time: 50 mins.            Max. Marks: 105
1.  An object AB of 
length 7.5 cm forms 
an inverted image 
A’B’ at the same 
place, when reflected 
from a concave mirror. A parallel ray from top 
of the object B, is incident on the mirror at the 
point P (not shown in figure). If PB’ = 25cm, 
find the focal length of the mirror.  
(a) 20 cm   (b) 15 cm 
(c) 10 cm   (d) 12.5 cm  
2. An object O is placed 
between a concave 
mirror and a plane 
mirror so that the first 
image in both the mirrors coincide at I. F is the 
focus of concave mirror. What should be the 
position of centre of curvature of concave 
mirror.  
(a) A   (b) B 
(c) C   (d) O  
3. A square slab is held in air. A ray 
of light strikes in the middle of 
face PQ at O
1
 so that it is 
internally reflected to strike again 
at O
1
. Find the angle of 
incidence, ? :  
(a) 30
0
   (b) 45
0
  
(c) 60
0
   (d) 90
0
  
4. A concave mirror of radius of curvature h is 
placed at the bottom of a tank containing a 
liquid of refractive index ? upto a depth d. An 
object P is placed at height h above the bottom 
of the mirror. Outside the liquid, an observer O 
views the object and its image in the mirror. The 
apparent distance between these two will be :  
P
h
d
O
 
(a) zero    (b) 
2h
?
 
(c) 
1
h1
??
?
??
?
??
  (d) 
2h
1 ??
 
5. An object is placed before a spherical mirror at a 
distance u. Its erect image is magnified six 
times. Find the distance between focus and the 
object :  
(a) u/4   (b) u/5 
(c) u/7   (d) u/3 
6. The distance between object and its erect but 
diminished image formed due to a spherical 
mirror is 3 times the distance between image 
and the focus while distance between object and 
focus is 2u. If the image is half in size than the 
object, find the distance of the object from the 
mirror:  
(a) 
3u
2
   (b) 
u
2
 
(c) u   (d) 
3u
4
 
P
Q
R
S
?
O
1
C B O A I
F
A
A’
B
B’
 
 
 
2 
PRACTICE SET 
OPTICS 
7. P, F and C are the pole, focus and centre of 
curvature of a convex mirror. There are two 
positions of images 
l2
and as shown, for an 
virtual object placed at different positions. The 
positions of the virtual object corresponding to 
I
1
 and I
2
 respectively will be:  
I
1
P F C I
2
 
 (a) between F and C, between C and I
2
  
 (b) between P and F, between F and C  
 (c) between P and C, between, C and I
2
  
 (d) between P and F, between C and I
2
  
8. In a vessel, as shown, point P is just visible 
when no liquid is filled in vessel through a 
telescope in the air. When liquid is filled in the 
vessel completely, point Q is visible without 
moving the vessel or telescope. Find the 
refractive index of the liquid.  
2R
R R
A
R R
Q
B
C
D
P
E
 
 (a) 2   (b) 3 
 (c) 
14
3
   (d) 
85
5
  
9. In the previous problem, what will be refractive 
index of the liquid so that point E is visible     
(PE = R/3) through the telescope in air when the 
vessel is filled with liquid completely, without 
moving the telescope and vessel :  
 (a) 2   (b) 3 
 (c) 1.5   (d) none of these  
For Problems (10-11) 
An object AB of height 1 cm lying on the axis of 
convex mirror of focal length 20 cm, at a distance of 
30 cm from its pole as shown in figure. Now the 
object starts moving with a constant speed 1 cm/sec 
towards the pole. Calculate  
1cm/s
1cm
O
30cm 20cm
F C
 
10. Magnitude of velocity of image at the given 
instant  
 (a) 0.16 cm/sec  (b) 0.32 cm/sec 
 (c) 0.08 cm/sec  (d) 0.64 cm/sec 
11. Rate of change of height of image.  
 (a) 0.016 cm/s  (b) 0.008 cm/s 
 (c) 0.16 cm/s  (d) 0.004 cm/s 
12. A cube of side 2 m is placed in front of a 
concave mirror of focal length 1 m with its 
face A at a distance of 3 m and face B at a 
distance of 5 m form the mirror, The distance 
between the images of face A and B and 
height of images of A and B are respectively. 
2m
B A
3m
2m
 
 (a) 1m, 0.5, 0.25 m  (b) 0.5 m, 1m, 0.25 m  
 (c) 0.5 m, 0.25 m, 1n (d) 0.25 m, 1m, 0.5 m. 
13. A fish rising vertically up toward the surface 
of water with speed 3 ms
?1
 observes a bird 
diving vertically down towards it with speed 
9 ms
?1
. The actual velocity of bird is:  
 
 (a)4.5 ms
-1
  (b) . ms
?1
54 
 (c) . ms
?1
30  (d) . ms
?1
34 
Page 3


 
 
1 
PRACTICE SET 
OPTICS 
CODE- 3006                                        SET-A 
Topics Covered: REFLECTION FROM PLANE & SPHERICAL SURFACE AND REFRACTION 
THROUGH PLANE SURFACE 
INSTRUCTIONS: 
(a) Problems from 1-20  are single correct Objective Problems.  
(b)   Problems from 21-25 are More than one correct Answer Problems. 
(c) Problems from 1-20 carry 4 marks each for correct option and -1 for every wrong attempt. 
(d) Problems from 21-25 carry 5 marks each for correct option and 0 for every wrong attempt. 
  
 Time: 50 mins.            Max. Marks: 105
1.  An object AB of 
length 7.5 cm forms 
an inverted image 
A’B’ at the same 
place, when reflected 
from a concave mirror. A parallel ray from top 
of the object B, is incident on the mirror at the 
point P (not shown in figure). If PB’ = 25cm, 
find the focal length of the mirror.  
(a) 20 cm   (b) 15 cm 
(c) 10 cm   (d) 12.5 cm  
2. An object O is placed 
between a concave 
mirror and a plane 
mirror so that the first 
image in both the mirrors coincide at I. F is the 
focus of concave mirror. What should be the 
position of centre of curvature of concave 
mirror.  
(a) A   (b) B 
(c) C   (d) O  
3. A square slab is held in air. A ray 
of light strikes in the middle of 
face PQ at O
1
 so that it is 
internally reflected to strike again 
at O
1
. Find the angle of 
incidence, ? :  
(a) 30
0
   (b) 45
0
  
(c) 60
0
   (d) 90
0
  
4. A concave mirror of radius of curvature h is 
placed at the bottom of a tank containing a 
liquid of refractive index ? upto a depth d. An 
object P is placed at height h above the bottom 
of the mirror. Outside the liquid, an observer O 
views the object and its image in the mirror. The 
apparent distance between these two will be :  
P
h
d
O
 
(a) zero    (b) 
2h
?
 
(c) 
1
h1
??
?
??
?
??
  (d) 
2h
1 ??
 
5. An object is placed before a spherical mirror at a 
distance u. Its erect image is magnified six 
times. Find the distance between focus and the 
object :  
(a) u/4   (b) u/5 
(c) u/7   (d) u/3 
6. The distance between object and its erect but 
diminished image formed due to a spherical 
mirror is 3 times the distance between image 
and the focus while distance between object and 
focus is 2u. If the image is half in size than the 
object, find the distance of the object from the 
mirror:  
(a) 
3u
2
   (b) 
u
2
 
(c) u   (d) 
3u
4
 
P
Q
R
S
?
O
1
C B O A I
F
A
A’
B
B’
 
 
 
2 
PRACTICE SET 
OPTICS 
7. P, F and C are the pole, focus and centre of 
curvature of a convex mirror. There are two 
positions of images 
l2
and as shown, for an 
virtual object placed at different positions. The 
positions of the virtual object corresponding to 
I
1
 and I
2
 respectively will be:  
I
1
P F C I
2
 
 (a) between F and C, between C and I
2
  
 (b) between P and F, between F and C  
 (c) between P and C, between, C and I
2
  
 (d) between P and F, between C and I
2
  
8. In a vessel, as shown, point P is just visible 
when no liquid is filled in vessel through a 
telescope in the air. When liquid is filled in the 
vessel completely, point Q is visible without 
moving the vessel or telescope. Find the 
refractive index of the liquid.  
2R
R R
A
R R
Q
B
C
D
P
E
 
 (a) 2   (b) 3 
 (c) 
14
3
   (d) 
85
5
  
9. In the previous problem, what will be refractive 
index of the liquid so that point E is visible     
(PE = R/3) through the telescope in air when the 
vessel is filled with liquid completely, without 
moving the telescope and vessel :  
 (a) 2   (b) 3 
 (c) 1.5   (d) none of these  
For Problems (10-11) 
An object AB of height 1 cm lying on the axis of 
convex mirror of focal length 20 cm, at a distance of 
30 cm from its pole as shown in figure. Now the 
object starts moving with a constant speed 1 cm/sec 
towards the pole. Calculate  
1cm/s
1cm
O
30cm 20cm
F C
 
10. Magnitude of velocity of image at the given 
instant  
 (a) 0.16 cm/sec  (b) 0.32 cm/sec 
 (c) 0.08 cm/sec  (d) 0.64 cm/sec 
11. Rate of change of height of image.  
 (a) 0.016 cm/s  (b) 0.008 cm/s 
 (c) 0.16 cm/s  (d) 0.004 cm/s 
12. A cube of side 2 m is placed in front of a 
concave mirror of focal length 1 m with its 
face A at a distance of 3 m and face B at a 
distance of 5 m form the mirror, The distance 
between the images of face A and B and 
height of images of A and B are respectively. 
2m
B A
3m
2m
 
 (a) 1m, 0.5, 0.25 m  (b) 0.5 m, 1m, 0.25 m  
 (c) 0.5 m, 0.25 m, 1n (d) 0.25 m, 1m, 0.5 m. 
13. A fish rising vertically up toward the surface 
of water with speed 3 ms
?1
 observes a bird 
diving vertically down towards it with speed 
9 ms
?1
. The actual velocity of bird is:  
 
 (a)4.5 ms
-1
  (b) . ms
?1
54 
 (c) . ms
?1
30  (d) . ms
?1
34 
 
 
3 
CLASS QUIZ -  LAWS OF MOTION 
 
 
TEST- CODE-3107-BOOKLET CODE-B 
PRACTICE SET 
OPTICS 
14. A concave mirror of focal length 10 cm and a 
convex mirror of focal length 15 cm are 
placed facing each other 40 cm apart. A point 
object is placed between the mirrors, on their 
common axis and 15 cm from the concave 
mirror. Find the position and nature of the 
image produced by the successive reflections, 
first at concave mirror and then at convex 
mirror. 
 (a) 12 cm behind convex mirror, real 
 (b) 9 cm behind convex mirror, real 
 (c) 6 cm behind convex mirror, virtual 
 (d)  3 cm behind convex mirror, virtual 
15. A linear object AB is placed along the axis of 
a concave mirror. The object is moving 
towards the mirror with speed U. The speed 
of the image of the point A is 4U and the 
speed of the image of B is also 4U but in 
opposite direction. If the center of the line 
AB is at a distance L from the mirror then 
find out the length of the object. 
 
A B
 
 (a) 3L/2  (b) 5L/3  
 (c) L   (d) None 
16. In a thick glass slab of thickness and 
refractive index n
1,
 a cuboidal cavity of 
thickness ‘m’ is carved as shown in the fig 
and is filled with liquid of R.I. n
2
 (n
1
 > n
2
). 
The ratio of /m , so that shift produced by 
this slab is zero when an observer A observes 
an object B with paraxial rays is: 
1
2 m
l
B
A
air
n
2
air
 
 (a)  
?
?
12
2
nn
n1
  (b) 
?
?
12
21
nn
n (n 1)
 
 (c) 
?
?
12
1
nn
n1
  (d) 
?
?
12
12
nn
n (n 1)
  
17. In the fig shown find the total magnification 
after two successive reflections first on M
1
 & 
then on M
2
  
 
 
 (a) +1   (b) ?2  
 (c) +2   (d) ?1 
18. A particle revolves in clockwise direction (as 
seen from point A) in a circle C of radius 
1cm and completes on revolution in 2 sec. 
The axis of the circle and the principal axis of 
the mirror M coincide, call it AB. The radius 
of curvature of the mirror is 20cm. Then the 
direction of revolution (as seen from A) of 
the image of the particle and its speed is  
 
 
 (a) clockwise, 1.57 cms
-1
  
 (b) clockwise, 3.14 cms
-1 
 (c) anticlockwise, 1.57 cms
-1 
 (d) anticlockwise, 3.14 cms
-1
  
19. Choose the correct mirror – image of figure 
given below 
 
 
 
 
Page 4


 
 
1 
PRACTICE SET 
OPTICS 
CODE- 3006                                        SET-A 
Topics Covered: REFLECTION FROM PLANE & SPHERICAL SURFACE AND REFRACTION 
THROUGH PLANE SURFACE 
INSTRUCTIONS: 
(a) Problems from 1-20  are single correct Objective Problems.  
(b)   Problems from 21-25 are More than one correct Answer Problems. 
(c) Problems from 1-20 carry 4 marks each for correct option and -1 for every wrong attempt. 
(d) Problems from 21-25 carry 5 marks each for correct option and 0 for every wrong attempt. 
  
 Time: 50 mins.            Max. Marks: 105
1.  An object AB of 
length 7.5 cm forms 
an inverted image 
A’B’ at the same 
place, when reflected 
from a concave mirror. A parallel ray from top 
of the object B, is incident on the mirror at the 
point P (not shown in figure). If PB’ = 25cm, 
find the focal length of the mirror.  
(a) 20 cm   (b) 15 cm 
(c) 10 cm   (d) 12.5 cm  
2. An object O is placed 
between a concave 
mirror and a plane 
mirror so that the first 
image in both the mirrors coincide at I. F is the 
focus of concave mirror. What should be the 
position of centre of curvature of concave 
mirror.  
(a) A   (b) B 
(c) C   (d) O  
3. A square slab is held in air. A ray 
of light strikes in the middle of 
face PQ at O
1
 so that it is 
internally reflected to strike again 
at O
1
. Find the angle of 
incidence, ? :  
(a) 30
0
   (b) 45
0
  
(c) 60
0
   (d) 90
0
  
4. A concave mirror of radius of curvature h is 
placed at the bottom of a tank containing a 
liquid of refractive index ? upto a depth d. An 
object P is placed at height h above the bottom 
of the mirror. Outside the liquid, an observer O 
views the object and its image in the mirror. The 
apparent distance between these two will be :  
P
h
d
O
 
(a) zero    (b) 
2h
?
 
(c) 
1
h1
??
?
??
?
??
  (d) 
2h
1 ??
 
5. An object is placed before a spherical mirror at a 
distance u. Its erect image is magnified six 
times. Find the distance between focus and the 
object :  
(a) u/4   (b) u/5 
(c) u/7   (d) u/3 
6. The distance between object and its erect but 
diminished image formed due to a spherical 
mirror is 3 times the distance between image 
and the focus while distance between object and 
focus is 2u. If the image is half in size than the 
object, find the distance of the object from the 
mirror:  
(a) 
3u
2
   (b) 
u
2
 
(c) u   (d) 
3u
4
 
P
Q
R
S
?
O
1
C B O A I
F
A
A’
B
B’
 
 
 
2 
PRACTICE SET 
OPTICS 
7. P, F and C are the pole, focus and centre of 
curvature of a convex mirror. There are two 
positions of images 
l2
and as shown, for an 
virtual object placed at different positions. The 
positions of the virtual object corresponding to 
I
1
 and I
2
 respectively will be:  
I
1
P F C I
2
 
 (a) between F and C, between C and I
2
  
 (b) between P and F, between F and C  
 (c) between P and C, between, C and I
2
  
 (d) between P and F, between C and I
2
  
8. In a vessel, as shown, point P is just visible 
when no liquid is filled in vessel through a 
telescope in the air. When liquid is filled in the 
vessel completely, point Q is visible without 
moving the vessel or telescope. Find the 
refractive index of the liquid.  
2R
R R
A
R R
Q
B
C
D
P
E
 
 (a) 2   (b) 3 
 (c) 
14
3
   (d) 
85
5
  
9. In the previous problem, what will be refractive 
index of the liquid so that point E is visible     
(PE = R/3) through the telescope in air when the 
vessel is filled with liquid completely, without 
moving the telescope and vessel :  
 (a) 2   (b) 3 
 (c) 1.5   (d) none of these  
For Problems (10-11) 
An object AB of height 1 cm lying on the axis of 
convex mirror of focal length 20 cm, at a distance of 
30 cm from its pole as shown in figure. Now the 
object starts moving with a constant speed 1 cm/sec 
towards the pole. Calculate  
1cm/s
1cm
O
30cm 20cm
F C
 
10. Magnitude of velocity of image at the given 
instant  
 (a) 0.16 cm/sec  (b) 0.32 cm/sec 
 (c) 0.08 cm/sec  (d) 0.64 cm/sec 
11. Rate of change of height of image.  
 (a) 0.016 cm/s  (b) 0.008 cm/s 
 (c) 0.16 cm/s  (d) 0.004 cm/s 
12. A cube of side 2 m is placed in front of a 
concave mirror of focal length 1 m with its 
face A at a distance of 3 m and face B at a 
distance of 5 m form the mirror, The distance 
between the images of face A and B and 
height of images of A and B are respectively. 
2m
B A
3m
2m
 
 (a) 1m, 0.5, 0.25 m  (b) 0.5 m, 1m, 0.25 m  
 (c) 0.5 m, 0.25 m, 1n (d) 0.25 m, 1m, 0.5 m. 
13. A fish rising vertically up toward the surface 
of water with speed 3 ms
?1
 observes a bird 
diving vertically down towards it with speed 
9 ms
?1
. The actual velocity of bird is:  
 
 (a)4.5 ms
-1
  (b) . ms
?1
54 
 (c) . ms
?1
30  (d) . ms
?1
34 
 
 
3 
CLASS QUIZ -  LAWS OF MOTION 
 
 
TEST- CODE-3107-BOOKLET CODE-B 
PRACTICE SET 
OPTICS 
14. A concave mirror of focal length 10 cm and a 
convex mirror of focal length 15 cm are 
placed facing each other 40 cm apart. A point 
object is placed between the mirrors, on their 
common axis and 15 cm from the concave 
mirror. Find the position and nature of the 
image produced by the successive reflections, 
first at concave mirror and then at convex 
mirror. 
 (a) 12 cm behind convex mirror, real 
 (b) 9 cm behind convex mirror, real 
 (c) 6 cm behind convex mirror, virtual 
 (d)  3 cm behind convex mirror, virtual 
15. A linear object AB is placed along the axis of 
a concave mirror. The object is moving 
towards the mirror with speed U. The speed 
of the image of the point A is 4U and the 
speed of the image of B is also 4U but in 
opposite direction. If the center of the line 
AB is at a distance L from the mirror then 
find out the length of the object. 
 
A B
 
 (a) 3L/2  (b) 5L/3  
 (c) L   (d) None 
16. In a thick glass slab of thickness and 
refractive index n
1,
 a cuboidal cavity of 
thickness ‘m’ is carved as shown in the fig 
and is filled with liquid of R.I. n
2
 (n
1
 > n
2
). 
The ratio of /m , so that shift produced by 
this slab is zero when an observer A observes 
an object B with paraxial rays is: 
1
2 m
l
B
A
air
n
2
air
 
 (a)  
?
?
12
2
nn
n1
  (b) 
?
?
12
21
nn
n (n 1)
 
 (c) 
?
?
12
1
nn
n1
  (d) 
?
?
12
12
nn
n (n 1)
  
17. In the fig shown find the total magnification 
after two successive reflections first on M
1
 & 
then on M
2
  
 
 
 (a) +1   (b) ?2  
 (c) +2   (d) ?1 
18. A particle revolves in clockwise direction (as 
seen from point A) in a circle C of radius 
1cm and completes on revolution in 2 sec. 
The axis of the circle and the principal axis of 
the mirror M coincide, call it AB. The radius 
of curvature of the mirror is 20cm. Then the 
direction of revolution (as seen from A) of 
the image of the particle and its speed is  
 
 
 (a) clockwise, 1.57 cms
-1
  
 (b) clockwise, 3.14 cms
-1 
 (c) anticlockwise, 1.57 cms
-1 
 (d) anticlockwise, 3.14 cms
-1
  
19. Choose the correct mirror – image of figure 
given below 
 
 
 
 
 
 
 
4 
PRACTICE SET 
OPTICS 
20. A point object is placed in front of a thick 
plane mirror as shown in figure below. Find 
the location of final image w.r.t. object. 
?=3/2
10cm
5cm
O
 
 (a) 
15
cm
2
   (b) 15 cm 
 (c) 
40
cm
3
   (d) 
80
cm
3
 
21. The diagram below shows 
an object located at point P, 
0.25 metre from concave 
spherical mirror with 
principal focus F. The focal length of the 
mirror is 0.10 metre.  
 How does the image change s the object is 
moved from point P toward point F?  
 (a) Its distance from the mirror decreases  
 (b) The size of image decrease  
 (c) Its distance from the mirror increases  
 (d) The size of image increases  
22. An object AB is placed parallel and close to 
the optical axis between focus F and centre of 
curvature C of a converging mirror of focal 
length f as shown in figure. 
A B
F C
 
 (a)  Image of A will be close than that of B 
 from the mirror. 
 (b)  Image of AB will be parallel to the 
 optical axis. 
 (c)  Image of AB will be straight line 
 inclined to the optical axis. 
 (d)  Image of AB will not be straight line. 
23. Which of the following statements is/are 
correct about the refraction of light from a 
plane surface when light ray is incident in 
denser medium. [C is critical angle] 
 (a)  The maximum angle of deviation during 
 refraction is C
2
?
??
?
??
??
, it will be at angle 
 of  incidence is C. 
 (b)  The maximum angle of deviation for all 
 angle of incidences is 2C ?? , when angle 
 of  incidence is slightly greater than C. 
 (c)  If angle of incidence is less than C then 
 deviation increases if angle of incidence 
 is also increased. 
 (d)  If angle of incidence is greater than C 
 then angle of deviation decreases if angle 
 of incidence is increased. 
24. A fish F, in the pond is at a depth of 0.8 m 
from the water surface and is moving 
vertically upwards with velocity 2 ms
-1
. At 
the same instant a bird B is at a height of 6 m 
from the water surface and is moving 
downwards with velocity 3 ms
-1
. At this 
instant both are on the same vertical lines as 
shown in the figure. Which of the following 
statements are correct? 
B
6m
3 ms
?1
2 ms
?1
F
0.8m
Air
Water
( =4/3) ?
 
 (a)  Height of B, observed by F (from itself) 
 is equal to 5.30 m 
 (b)  Depth of F, observed by B (from itself) 
 is equal to 6.60 m 
 (c)  Height of B, observed by F (from itself) 
 is equal to 8.80 m 
 (d)  None of the above 
25. In previous question, 
 (a)  velocity of B, observed by F (relative to 
 itself) is equal to 4.25 ms
-1
 
 (b)  velocity of B, observed by F (relative to 
 itself) is equal to 6 ms
-1 
 (c)  velocity of B, observed by F (relative to 
 itself) is equal to 5.50 ms
-1 
 (d)  velocity of F, observed by B (relative to 
 itself) is equal to 4.50 ms
-1
 
P F
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