Page 1
DIRECTIONS (Q.1-Q.21) : There are 21 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A thin prism of angle A = 6° produces a deviation d = 3°.
Find the refractive index of the material of prism.
(a) 1.5 (b) 1.0
(c) 2.5 (d) 0.5
Q.2 A ray of light is incident at an angle of 60° on one face of
a prism which has an angle of 30°. The ray emerging out of
the prism makes an angle of 30° with the incident ray.
Calculate the refractive index of the material of the prism
(a)1 (b)
2
(c)
3
(d)2
Q.3 Light of wavelength 6000Å enters from air into water
(a medium of refractive index 4/3). Find the speed and
wavelength [c = 3 × 10
8
m/s]
(a) 2.25 × 10
8
m/s, 4500Å (b) 1.25 × 10
8
m/s, 2500Å
(c) 3.15 × 10
8
m/s, 3500Å (d) 3.45 × 10
8
m/s, 5500Å
Q.4 A ray of light is incident on a transparent glass-slab of
refractive index 1.5. If the reflected and refracted rays are
mutually perpendicular, what is the angle of incidence ?
(a) 30° (b)
1
2
sin
3
-
(c)
1
2
tan
3
-
(d)
1
3
tan
2
-
Page 2
DIRECTIONS (Q.1-Q.21) : There are 21 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A thin prism of angle A = 6° produces a deviation d = 3°.
Find the refractive index of the material of prism.
(a) 1.5 (b) 1.0
(c) 2.5 (d) 0.5
Q.2 A ray of light is incident at an angle of 60° on one face of
a prism which has an angle of 30°. The ray emerging out of
the prism makes an angle of 30° with the incident ray.
Calculate the refractive index of the material of the prism
(a)1 (b)
2
(c)
3
(d)2
Q.3 Light of wavelength 6000Å enters from air into water
(a medium of refractive index 4/3). Find the speed and
wavelength [c = 3 × 10
8
m/s]
(a) 2.25 × 10
8
m/s, 4500Å (b) 1.25 × 10
8
m/s, 2500Å
(c) 3.15 × 10
8
m/s, 3500Å (d) 3.45 × 10
8
m/s, 5500Å
Q.4 A ray of light is incident on a transparent glass-slab of
refractive index 1.5. If the reflected and refracted rays are
mutually perpendicular, what is the angle of incidence ?
(a) 30° (b)
1
2
sin
3
-
(c)
1
2
tan
3
-
(d)
1
3
tan
2
-
2
DPP/ P 50
Q.5 An optical fibre consists of core of m
1
surrounded by a
cladding of m
2
< m
1
. A beam of light enters from air at an
angle a with axis of fibre. The highest a for which ray can
be travelled through fibre is
(a)
1 22
21
cos
-
m -m
a
m
2
m
1
(b)
1 22
12
sin
-
m -m
(c)
1 22
12
tan
-
m -m
(d)
1 22
12
sec
-
m -m
Q.6 A glass plate 4 mm thick is viewed from the above through
a microscope. The microscope must be lowered 2.58 mm
as the operator shifts from viewing the top surface to
viewing the bottom surface through the glass. What is the
index of refraction of the glass ?
(a) 1.61 (b) 1.55 (c) 3.24 (d) 1.21
Q.7 A vertical microscope is focussed on a point at the bottom
of an empty tank. Water (m = 4/3) is then poured into the
tank. The height of the water column is 4cm. Another lighter
liquid, which does not mix with water and which has
refractive index 3/2 is then poured over the water.The height
of liquid column is 2cm. What is the vertical distance
through which the microscope must be moved to bring the
object in focus again ?
(a) 2.61 m (b) 1.55 m (c) 3.12 m (d) 1.67 m
Q.8 Light from a sodium lamp (l
0
= 589 nm) passes through a
tank of glycerin (refractive index 1.47) 20m long in a time
t
1
. If it takes a time t
2
to traverse the same tank when filled
with carbon disulphide (index 1.63), then the difference t
2
–
t
1
is
(a) 6.67 × 10
-8
sec (b) 1.09 × 10
-7
sec
(c) 2.07 × 10
-7
sec (d) 1.07 × 10
-8
sec
Q.9 A light beam is travelling from Region I to Region IV (Refer
Figure). The refractive index in Regions I, II, III and IV are
n
0
,
000
nnn
, and
268
, respectively. The angle of incidence q
for which the beam just misses entering Region IV is
Region I Region II Region III
q
n
0
0
n
2
0
n
6
0
n
8
0.2 m
0.6 m
0
Region IV
(a)
1
3
sin
4
-
æö
ç÷
èø
(b)
1
1
sin
8
- æö
ç÷
èø
(c)
1
1
sin
4
-æö
ç÷
èø
(d)
1
1
sin
3
- æö
ç÷
èø
Q.10 The refractive index of the material of a prism is
2
and
its prism angle is 30º. One of its refracting faces is polished.
The incident beam of light will return back for the angle of
incidence
(a) 60º (b) 45º (c) 30º (d) 0º
Q.11 A ray of light incident on a prism surface at an angle of 50º
in the minimum deviation position. If the angle of prism is
60º then the values of d
m
and m will be respectively –
(sin 50º = 0.766)
(a) 40º and 1.532 (b) 60º and 1.532
(c) 90º and 1.532 (d) 0º and 1.532
Q.12 A glass prism of refractive index 1.5 and angle of prism 6º
is put in contact with another prism of refractive index 1.6
when a ray of light is made incident on this combination
normally then it emerges out undeviated. The angle of
second prism will be –
(a) 6º (b) 5º (c) 4º (d) 3º
Q.13 A crown glass prism of angle 5° is to be combined with a
flint glass prism in such a way that the mean ray passes
undeviated. Find the angle of the flint glass prism needed
and the angular dispersion produced by the combination
when white light goes through it. Refractive indices for
red, yellow and violet light are 1.514, 1.517 and 1.523
respectively for crown glass and 1.613, 1.620 and 1.632
for flint glass.
(a) 4.2°, 0.0348° (b) 4.2°, 0.0138°
(c) 1.2°, 0.0348° (d) 4.4°, 0.0218°
Q.14 Calculate the dispersive power for crown glass from the
(given data : m
v
= 1.5230, m
r
=1.5145)
(a) 0.0163 (b) 0.0183 (c) 0.0142 (d) 0.0112
Page 3
DIRECTIONS (Q.1-Q.21) : There are 21 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A thin prism of angle A = 6° produces a deviation d = 3°.
Find the refractive index of the material of prism.
(a) 1.5 (b) 1.0
(c) 2.5 (d) 0.5
Q.2 A ray of light is incident at an angle of 60° on one face of
a prism which has an angle of 30°. The ray emerging out of
the prism makes an angle of 30° with the incident ray.
Calculate the refractive index of the material of the prism
(a)1 (b)
2
(c)
3
(d)2
Q.3 Light of wavelength 6000Å enters from air into water
(a medium of refractive index 4/3). Find the speed and
wavelength [c = 3 × 10
8
m/s]
(a) 2.25 × 10
8
m/s, 4500Å (b) 1.25 × 10
8
m/s, 2500Å
(c) 3.15 × 10
8
m/s, 3500Å (d) 3.45 × 10
8
m/s, 5500Å
Q.4 A ray of light is incident on a transparent glass-slab of
refractive index 1.5. If the reflected and refracted rays are
mutually perpendicular, what is the angle of incidence ?
(a) 30° (b)
1
2
sin
3
-
(c)
1
2
tan
3
-
(d)
1
3
tan
2
-
2
DPP/ P 50
Q.5 An optical fibre consists of core of m
1
surrounded by a
cladding of m
2
< m
1
. A beam of light enters from air at an
angle a with axis of fibre. The highest a for which ray can
be travelled through fibre is
(a)
1 22
21
cos
-
m -m
a
m
2
m
1
(b)
1 22
12
sin
-
m -m
(c)
1 22
12
tan
-
m -m
(d)
1 22
12
sec
-
m -m
Q.6 A glass plate 4 mm thick is viewed from the above through
a microscope. The microscope must be lowered 2.58 mm
as the operator shifts from viewing the top surface to
viewing the bottom surface through the glass. What is the
index of refraction of the glass ?
(a) 1.61 (b) 1.55 (c) 3.24 (d) 1.21
Q.7 A vertical microscope is focussed on a point at the bottom
of an empty tank. Water (m = 4/3) is then poured into the
tank. The height of the water column is 4cm. Another lighter
liquid, which does not mix with water and which has
refractive index 3/2 is then poured over the water.The height
of liquid column is 2cm. What is the vertical distance
through which the microscope must be moved to bring the
object in focus again ?
(a) 2.61 m (b) 1.55 m (c) 3.12 m (d) 1.67 m
Q.8 Light from a sodium lamp (l
0
= 589 nm) passes through a
tank of glycerin (refractive index 1.47) 20m long in a time
t
1
. If it takes a time t
2
to traverse the same tank when filled
with carbon disulphide (index 1.63), then the difference t
2
–
t
1
is
(a) 6.67 × 10
-8
sec (b) 1.09 × 10
-7
sec
(c) 2.07 × 10
-7
sec (d) 1.07 × 10
-8
sec
Q.9 A light beam is travelling from Region I to Region IV (Refer
Figure). The refractive index in Regions I, II, III and IV are
n
0
,
000
nnn
, and
268
, respectively. The angle of incidence q
for which the beam just misses entering Region IV is
Region I Region II Region III
q
n
0
0
n
2
0
n
6
0
n
8
0.2 m
0.6 m
0
Region IV
(a)
1
3
sin
4
-
æö
ç÷
èø
(b)
1
1
sin
8
- æö
ç÷
èø
(c)
1
1
sin
4
-æö
ç÷
èø
(d)
1
1
sin
3
- æö
ç÷
èø
Q.10 The refractive index of the material of a prism is
2
and
its prism angle is 30º. One of its refracting faces is polished.
The incident beam of light will return back for the angle of
incidence
(a) 60º (b) 45º (c) 30º (d) 0º
Q.11 A ray of light incident on a prism surface at an angle of 50º
in the minimum deviation position. If the angle of prism is
60º then the values of d
m
and m will be respectively –
(sin 50º = 0.766)
(a) 40º and 1.532 (b) 60º and 1.532
(c) 90º and 1.532 (d) 0º and 1.532
Q.12 A glass prism of refractive index 1.5 and angle of prism 6º
is put in contact with another prism of refractive index 1.6
when a ray of light is made incident on this combination
normally then it emerges out undeviated. The angle of
second prism will be –
(a) 6º (b) 5º (c) 4º (d) 3º
Q.13 A crown glass prism of angle 5° is to be combined with a
flint glass prism in such a way that the mean ray passes
undeviated. Find the angle of the flint glass prism needed
and the angular dispersion produced by the combination
when white light goes through it. Refractive indices for
red, yellow and violet light are 1.514, 1.517 and 1.523
respectively for crown glass and 1.613, 1.620 and 1.632
for flint glass.
(a) 4.2°, 0.0348° (b) 4.2°, 0.0138°
(c) 1.2°, 0.0348° (d) 4.4°, 0.0218°
Q.14 Calculate the dispersive power for crown glass from the
(given data : m
v
= 1.5230, m
r
=1.5145)
(a) 0.0163 (b) 0.0183 (c) 0.0142 (d) 0.0112
DPP/ P 50
3
Q.15A prism of dispersive power 0.021 and refractive index
1.53 form an achromatic combination with prism of angle
4.2° and dispersive power 0.045 having refractive index
1.65. Find the resultant deviation.
(a) 1.12° (b) 2.16° (c) 3.12° (d) 4.18°
Q.16 A ray of light fall normally on a refracting face of a prism
of refractive index 1.5. Find the angle of the prism if the
ray just fails to emerge from the prism.
(a) 55° (b) 22° (c) 12° (d) 42°
Q.17 The refractive indices of material of a prism for blue and
red colours are 1.532 and 1.514 respectively. Calculate
angular dispersion produced by the prism if angle of prism
is 8°.
(a) 0.144° (b) 0.122° (c) 0.133° (d) 0.111°
Q.18 A ball is dropped from a height of 20 m above the surface
of water in a lake. The refractive index of water is 4/3. A
fish inside the lake, in the line of fall of the ball, is looking
at the ball. At an instant, when the ball is 12.8 m above the
water surface, the fish sees the speed of ball as [g = 10 m/
s
2
]
(a) 9 m/s (b) 12 m/s (c) 16 m/s (d) 21.33 m/s
Q.19 The dispersive powers of crown and flint glasses are 0.03
and 0.05 respectively. The refractive indices for yellow
light for these glasses are 1.517 and 1.621 respectively .
It is desired to form an achromatic combination of prisms
of crown and flint glasses which can produce a deviation
of 1° in the yellow ray. The refracting angle of the flint
glass prism is
(a) 2.4° (b) 1.4° (c) 3.4° (d) 5.2°
Q.20A glass prism (m = 1.5) is dipped in water ( m = 4/3) as
shown in figure. A light ray is incident normally on the
surface AB. It reaches the surface BC after T.I.R
q
C
B A
(a) sin q ³ 8/9 (b) 2/3 < sin q < 8/9
(c) sin q £ 2/3 (d) It is not possible
Q.21 A prism having an apex angle 4° and refraction index 1.5
is located in front of a vertical plane mirror as shown in
figure. Through what total angle is the ray deviated after
reflection from the mirror
90°
4°
(a) 176° (b) 4°
(c) 178° (d) 2°
DIRECTIONS (Q.22-Q.24) : In the following questions,
more than one of the answers given are correct. Select the
correct answers and mark it according to the following
codes:
Codes :
(a) 1, 2 and 3 are correct (b) 1 and 2 are correct
(c) 2 and 4 are correct (d) 1 and 3 are correct
Q.22A ray of monochromatic light is incident on the plane
surface of separation between two media x and y with angle
of incidence i in the medium x and angle of refraction r in
the medium y. The graph shows the relation between sin i
and sin r.
30°
sin i
sin r
(1) The speed of light in the medium y is 3 times than in
medium x
(2) The speed of light in the medium y is
1
3
times than in
medium x.
(3) The total internal reflection can take place when the
incidence is in x.
(4) The total internal reflection can take place when the
incidence is in y
Page 4
DIRECTIONS (Q.1-Q.21) : There are 21 multiple choice
questions. Each question has 4 choices (a), (b), (c) and (d), out
of which ONLY ONE choice is correct.
Q.1 A thin prism of angle A = 6° produces a deviation d = 3°.
Find the refractive index of the material of prism.
(a) 1.5 (b) 1.0
(c) 2.5 (d) 0.5
Q.2 A ray of light is incident at an angle of 60° on one face of
a prism which has an angle of 30°. The ray emerging out of
the prism makes an angle of 30° with the incident ray.
Calculate the refractive index of the material of the prism
(a)1 (b)
2
(c)
3
(d)2
Q.3 Light of wavelength 6000Å enters from air into water
(a medium of refractive index 4/3). Find the speed and
wavelength [c = 3 × 10
8
m/s]
(a) 2.25 × 10
8
m/s, 4500Å (b) 1.25 × 10
8
m/s, 2500Å
(c) 3.15 × 10
8
m/s, 3500Å (d) 3.45 × 10
8
m/s, 5500Å
Q.4 A ray of light is incident on a transparent glass-slab of
refractive index 1.5. If the reflected and refracted rays are
mutually perpendicular, what is the angle of incidence ?
(a) 30° (b)
1
2
sin
3
-
(c)
1
2
tan
3
-
(d)
1
3
tan
2
-
2
DPP/ P 50
Q.5 An optical fibre consists of core of m
1
surrounded by a
cladding of m
2
< m
1
. A beam of light enters from air at an
angle a with axis of fibre. The highest a for which ray can
be travelled through fibre is
(a)
1 22
21
cos
-
m -m
a
m
2
m
1
(b)
1 22
12
sin
-
m -m
(c)
1 22
12
tan
-
m -m
(d)
1 22
12
sec
-
m -m
Q.6 A glass plate 4 mm thick is viewed from the above through
a microscope. The microscope must be lowered 2.58 mm
as the operator shifts from viewing the top surface to
viewing the bottom surface through the glass. What is the
index of refraction of the glass ?
(a) 1.61 (b) 1.55 (c) 3.24 (d) 1.21
Q.7 A vertical microscope is focussed on a point at the bottom
of an empty tank. Water (m = 4/3) is then poured into the
tank. The height of the water column is 4cm. Another lighter
liquid, which does not mix with water and which has
refractive index 3/2 is then poured over the water.The height
of liquid column is 2cm. What is the vertical distance
through which the microscope must be moved to bring the
object in focus again ?
(a) 2.61 m (b) 1.55 m (c) 3.12 m (d) 1.67 m
Q.8 Light from a sodium lamp (l
0
= 589 nm) passes through a
tank of glycerin (refractive index 1.47) 20m long in a time
t
1
. If it takes a time t
2
to traverse the same tank when filled
with carbon disulphide (index 1.63), then the difference t
2
–
t
1
is
(a) 6.67 × 10
-8
sec (b) 1.09 × 10
-7
sec
(c) 2.07 × 10
-7
sec (d) 1.07 × 10
-8
sec
Q.9 A light beam is travelling from Region I to Region IV (Refer
Figure). The refractive index in Regions I, II, III and IV are
n
0
,
000
nnn
, and
268
, respectively. The angle of incidence q
for which the beam just misses entering Region IV is
Region I Region II Region III
q
n
0
0
n
2
0
n
6
0
n
8
0.2 m
0.6 m
0
Region IV
(a)
1
3
sin
4
-
æö
ç÷
èø
(b)
1
1
sin
8
- æö
ç÷
èø
(c)
1
1
sin
4
-æö
ç÷
èø
(d)
1
1
sin
3
- æö
ç÷
èø
Q.10 The refractive index of the material of a prism is
2
and
its prism angle is 30º. One of its refracting faces is polished.
The incident beam of light will return back for the angle of
incidence
(a) 60º (b) 45º (c) 30º (d) 0º
Q.11 A ray of light incident on a prism surface at an angle of 50º
in the minimum deviation position. If the angle of prism is
60º then the values of d
m
and m will be respectively –
(sin 50º = 0.766)
(a) 40º and 1.532 (b) 60º and 1.532
(c) 90º and 1.532 (d) 0º and 1.532
Q.12 A glass prism of refractive index 1.5 and angle of prism 6º
is put in contact with another prism of refractive index 1.6
when a ray of light is made incident on this combination
normally then it emerges out undeviated. The angle of
second prism will be –
(a) 6º (b) 5º (c) 4º (d) 3º
Q.13 A crown glass prism of angle 5° is to be combined with a
flint glass prism in such a way that the mean ray passes
undeviated. Find the angle of the flint glass prism needed
and the angular dispersion produced by the combination
when white light goes through it. Refractive indices for
red, yellow and violet light are 1.514, 1.517 and 1.523
respectively for crown glass and 1.613, 1.620 and 1.632
for flint glass.
(a) 4.2°, 0.0348° (b) 4.2°, 0.0138°
(c) 1.2°, 0.0348° (d) 4.4°, 0.0218°
Q.14 Calculate the dispersive power for crown glass from the
(given data : m
v
= 1.5230, m
r
=1.5145)
(a) 0.0163 (b) 0.0183 (c) 0.0142 (d) 0.0112
DPP/ P 50
3
Q.15A prism of dispersive power 0.021 and refractive index
1.53 form an achromatic combination with prism of angle
4.2° and dispersive power 0.045 having refractive index
1.65. Find the resultant deviation.
(a) 1.12° (b) 2.16° (c) 3.12° (d) 4.18°
Q.16 A ray of light fall normally on a refracting face of a prism
of refractive index 1.5. Find the angle of the prism if the
ray just fails to emerge from the prism.
(a) 55° (b) 22° (c) 12° (d) 42°
Q.17 The refractive indices of material of a prism for blue and
red colours are 1.532 and 1.514 respectively. Calculate
angular dispersion produced by the prism if angle of prism
is 8°.
(a) 0.144° (b) 0.122° (c) 0.133° (d) 0.111°
Q.18 A ball is dropped from a height of 20 m above the surface
of water in a lake. The refractive index of water is 4/3. A
fish inside the lake, in the line of fall of the ball, is looking
at the ball. At an instant, when the ball is 12.8 m above the
water surface, the fish sees the speed of ball as [g = 10 m/
s
2
]
(a) 9 m/s (b) 12 m/s (c) 16 m/s (d) 21.33 m/s
Q.19 The dispersive powers of crown and flint glasses are 0.03
and 0.05 respectively. The refractive indices for yellow
light for these glasses are 1.517 and 1.621 respectively .
It is desired to form an achromatic combination of prisms
of crown and flint glasses which can produce a deviation
of 1° in the yellow ray. The refracting angle of the flint
glass prism is
(a) 2.4° (b) 1.4° (c) 3.4° (d) 5.2°
Q.20A glass prism (m = 1.5) is dipped in water ( m = 4/3) as
shown in figure. A light ray is incident normally on the
surface AB. It reaches the surface BC after T.I.R
q
C
B A
(a) sin q ³ 8/9 (b) 2/3 < sin q < 8/9
(c) sin q £ 2/3 (d) It is not possible
Q.21 A prism having an apex angle 4° and refraction index 1.5
is located in front of a vertical plane mirror as shown in
figure. Through what total angle is the ray deviated after
reflection from the mirror
90°
4°
(a) 176° (b) 4°
(c) 178° (d) 2°
DIRECTIONS (Q.22-Q.24) : In the following questions,
more than one of the answers given are correct. Select the
correct answers and mark it according to the following
codes:
Codes :
(a) 1, 2 and 3 are correct (b) 1 and 2 are correct
(c) 2 and 4 are correct (d) 1 and 3 are correct
Q.22A ray of monochromatic light is incident on the plane
surface of separation between two media x and y with angle
of incidence i in the medium x and angle of refraction r in
the medium y. The graph shows the relation between sin i
and sin r.
30°
sin i
sin r
(1) The speed of light in the medium y is 3 times than in
medium x
(2) The speed of light in the medium y is
1
3
times than in
medium x.
(3) The total internal reflection can take place when the
incidence is in x.
(4) The total internal reflection can take place when the
incidence is in y
4
DPP/ P 50
Space for Rough Work
Q.23 Dispersive power does not depend upon
(1) The shape of prism (2) Angle of prism
(3) Height of the prism (4) Material of prism
Q.24 The wrong statements are
(1) The order of colours in the primary and the secondary
rainbows is the same
(2) The intensity of colours in the primary and the
secondary rainbows is the same
(3) The intensity of light in the primary rainbow is greater
and the order of colours is the same than the secondary
rainbow
(4) The intensity of light for different colours in primary
rainbow is greater and the order of colours is reverse
as that in the secondary rainbow
DIRECTIONS (Qs. 25-Q.27) : Each of these questions contains
two statements: Statement-1 (Assertion) and Statement-2
(Reason). Each of these questions has four alternative choices,
only one of which is the correct answer. You have to select the
correct choice.
(a) Statement-1 is True, Statement-2 is True; Statement-2 is a
correct explanation for Statement-1.
(b) Statement-1 is True, Statement-2 is True; Statement-2 is
NOT a correct explanation for Statement-1.
(c) Statement -1 is False, Statement-2 is True.
(d) Statement -1 is True, Statement-2 is False.
Q.25 Statement-1: There is no dispersion of light refracted
through a rectangular glass slab.
Statement-2: Dispersion of light is the phenomenon of
splitting of a beam of white light into its constituent
colours.
Q.26 Statement-1: Dispersion of light occurs because velocity
of light in a material depends upon its colour.
Statement-2: The dispersive power depends only upon the
material of the prism, not upon the refracting angle of the
prism.
Q.27 Statement-1: If a plane glass slab is placed on the letters
of different colours all the letters appear to be raised up to
the same height.
Statement-2: Different colours have different
wavelengths.
23. 24. 25. 26. 27. RESPONSE GRID
Total Questions 27 Total Marks 108
Attempted Correct
Incorrect Net Score
Cut-off Score 28 Qualifying Score 46
DAILY PRACTICE PROBLEM SHEET 50 - PHYSICS
Success Gap = Net Score – Qualifying Score
Net Score = (Correct × 4) – (Incorrect × 1)
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