Gop Rees
Gop Rees
as shown in the figure. Find, the co- Principle axis of concave lens
ordinate of the final image formed by the (0,0) 5 mm
Principle axis of convex lens
combination if parallel beam of light is
incident on lens origin is at the optical
centre of convex lens. 30 cm
(A) (25 cm, 0.5 cm) (B) (25 cm, 0.25 cm)
(C) (25 cm, 0.5 cm) (D) (25 cm, −0.25 cm)
3. A ray of light is incident on a plane mirror along a line represented by ˆi + ˆj + kˆ . The possible
vector orientation parallel to the plane of the mirror to get the light retraced is
(A) 2iˆ − 4ˆj + 2kˆ (B) ˆi − ˆj − kˆ
(C) 2iˆ + ˆj − 2kˆ (D) −ˆi − ˆj − kˆ
4. A slab of thickness 10 cm is kept on x-y plane (z=0) and its refractive index varies as
Z
µ = 1.63 1 + where Z is in cm. If it is viewed from top its apparent thickness will be (in cm)
20
(A) 5 (B) 6
(C) 4 (D) 3
(C)
R ( 3 −1) (D) none of these
D
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RANK ENHANCEMENT SHEET GEOMETRICAL OPTICS JEE Advance
8. In the displacement method, magnifications for two positions of the lens are 3 and 2 and distance
between the two positions of lens is 30 cm. The focal length of the lens is
(A) 30 cm (B) 20 cm
(C) 10 cm (D) 15 cm
9. The critical angle for a prism and its surrounding interface is 36°. The maximum angle of prism
for which any emergent ray is possible is
(A) 18° (B) 36°
(C) 72° (D) 144°
10. The adjacent figure shows cross section of a hollow glass tube of C B
internal radius r, external radius R and index of refraction n. For two r1 A
rays DE and ABC (in which DE lies on ODE and DE and BC are or
parallel), the separation r1 will be E D air
(A) r1 = (n − 1)R
2
(B) r1 = n R glass
2
(C) r1 = nr (D) r1 = n r
A′
θ
θ O A B
(A) B′ A′ O A B
B′ (D) B′
A′
θ A′ θ
(C) O A B O A B
12. ABCD represents a square glass block of refractive index 3/2. An object O is O
A B
placed near the face AB as shown. When observed from face AD, the object will
(A) appear midway between A and D (B) appear nearer to A
(C) appear nearer to D (D) not be seen at all
D C
13. STATEMENT-1: The focal length of a lens depends on the material of the lens but the focal
length of a mirror is independent of the material from which the mirror is made.
because
STATEMENT-2: Law of reflection is independent of material and surrounding medium where as
law of refraction depends on the mediums.
(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.
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14. An object is moving with speed v parallel to mirror M2. Relative velocity M1
of the image in M1 w.r.t. the image in mirror M2 will be
(A) 2v sin2α (B) 2v sinα
α
2v
(C) (D) 2v tanα
sin2α
v
M2
O Observer
15. Two identical rectangular glass-
slabs of different materials whose
P″″ B′′ air
height is 1m has a thin cylindrical
wire. Observer is situated at O in M Interface
16. A light ray incident along vector 2iˆ + 4ˆj + 5kˆ strikes on the x-z plane from medium I of
refractive index 3 and enters into medium II of refractive index is µ2. The value of µ2 for which
the value of angle of refraction becomes 90°, is
4 3 3 3
(A) (B)
5 5
2 3 3
(C) (D)
5 5
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R
18. The image of a point source, kept at origin O,
10 cm
forms at point A due to transparent sphere of 40 cm
radius 10 cm as shown in the figure. Here OX is
O P C Q A x
the optical axis of the sphere. Now, the sphere is
cut into two equal parts, along a plane
S
perpendicular to the horizontal axis OX and the
plane surface of the left half (PRCS) is silvered.
The right half (PQSC) is removed. Now the co-
ordinate of image of point source O formed by
remaining silvered hemisphere will be
(A) (10 cm, 0) (B) (20 cm, 0)
(C) (30 cm, 0) (D) (40 cm, 0)
Ist Refracting IInd Refracting
surface surface
19. Upper part of a prism is cut. Ray diagram of a ray incident
36°° 32°°
at first refracting surface is as shown in the diagram.
Minimum deviation that can be given by two refracting 67°° 53°°
surfaces for any ray may be
(A) 10°
(B) 12°
(C) 8°
(D) less than 8°
21. A black spot is present just inside one of the face of an equilateral prism. A
man places his eye directly at the opposite corner. He sees two images of
o
the spot at an angular separation of 60 . Then the minimum value of
refractive index of the prism is:
3
(A) µ = (B) µ = 2
2
3 2
(C) µ = (D) µ =
2 3
Black spot
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RANK ENHANCEMENT SHEET GEOMETRICAL OPTICS JEE Advance
22. The refractive index of space changes with y, whose function is given as
y B
1 if y≤0 2y0
µ(y) = ky 2 if 0 ≤ y ≤ 2y 0 y0
2 if 2y 0 ≤ y ≤ 4y 0 A x
y α
where k and are positive constant. When a light ray is incident at point A as shown in figure.
When the ray reaches to point B, it becomes parallel to xz-plane. Choose the correct statement.
(A) α is independent of k (B) α is independent of
(C) α is independent of both k and (D) none of these
23. The plane side of a thin plano convex lens is silvered so that the lens acts as concave mirror of
focal length 40 cm. The material of lens has refractive index 1.5. The radius of curvature of the
curved surface of the lens is
(A) 30 cm (B) 40 cm
(C) 50 cm (D) 60 cm
v
(A) Velocity of light spot formed on the wall is î d x
2
(B) Light spot is at rest
(C) size of the light spot would increase
(D) size of the light spot would remains same.
COMPREHENSION TYPE
A small fish touching the surface of a spherical air bubble is observed from µ=4/3
opposite surface from point P. The diameter of bubble is 12 cm. (Refractive
index of water is 4/3). Answer following questions on basis of above said P
B
situation. A 12cm
N
A ray goes from medium I to medium II of refractive indices as µ1
and µ2 respectively [As shown in the figure]. The Medium II
µ2 Interface
refractive index of medium I and medium II can be
Medium I O
changed and hypothetically their ranges are given by 1 ≤ µ1
µ1 < ∞ and 1 ≤ µ2 < ∞. i = 60°°
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6. The phenomenon of total internal reflection will take place in the which region
(A) I (B) II
(C) III (D) none of the above
An experiment is performed on thin lens in order to determine the radii R1 and R2 of the curvature of its two
surfaces and the refractive index ‘µ’ of its glass.
Experiment I: A real object is placed 36 cm to the left of lens and a real image is formed 72 cm to the right
of lens.
Experiment II: The lens is floated on the surface of mercury with surface having radius of curvature R2
faces air. A real object is placed at 60 cm above it, and a real image is formed at 30 cm above it (assume
mercury to be perfectly reflecting).
Experiment III: The lens is floated on the surface of mercury with surface having radius of curvature R1
20
faces air. A real object is placed at 7.5 cm above it and real image is formed at cm above it. On the
3
bases of Experiments I, II and III, answer the following questions.
8. The magnitude of R1 is
(A) 60 cm (B) 30 cm
(C) 120 cm (D) 45 cm
R1 R2
R1 R2
Biconvex Biconcave
(C) (D)
R2 R1
R2 R1
Convexo-concave Concavo-convex
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14. If source moves downwards with velocity 4 cm/s, its image will move with speed
8
(A) 6 cm/sec (B) cm/sec
3
72
(C) cm/sec (D) None
3
15. If convex lens L2 is replaced by plane mirror, then final coordinate of image will be
(A) (28 cm, 2 cm) (B) (30 cm, 2 cm)
(C) (30 cm, -2 cm) (D) (30 cm, 3 cm)
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RANK ENHANCEMENT SHEET GEOMETRICAL OPTICS JEE Advance
Column I Column II
(A) L1 shifts slightly to right (p) Image I shifts slightly to right
(B) L1 shifts slightly up (q) Image I shifts slightly to left
(C) L2 shifts slightly to right (r) No shift of Image I along axis
(D) L2 shifts slightly up (s) Image I becomes bigger
(t) Image I becomes smaller
2. Match the following graphs (in column – II) between position of object (u) and position of image (v).
Take positive sign in the direction of ray.
Column – I Column – II
v
(A) Concave mirror (p)
O
u
v
(B) Convex mirror (q)
O
u
v
(C) Convex lens (r)
O
u
v
(D) Concave lens (s)
O
u
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RANK ENHANCEMENT SHEET GEOMETRICAL OPTICS JEE Advance
Plane mirror
air
moving towards child with a velocity of 4 cm/s as µ = 4/3 4 cm/s
3 cm/s
shown in the figure. The wall behind the fish is silvered
(Refractive index of water is µ = 4/3). Match the
following
Column – I Column – II
(A) Velocity of child as observed by fish by one refraction only (p) zero
(B) Velocity of fish as observed by child by one refraction only (q) 6 cm/s
(C) Velocity of image of fish by reflection from mirror as (r) 8 cm/s
observed by child.
(D) Velocity of image of child by reflection from mirror as (s) 7 m/s
observed by fish
Column I Column II
(A) Object is kept at point (−a, 0) and µ1 < µ2 (p) Image may be real
(B) Object is kept at point (−a, 0) and µ1 > µ2 (q) Image may be virtual
(C) Object is kept at point (+a, 0) and µ1 < µ2 (r) The position of image may be in between the
position of object and origin.
(D) Object is kept at point (+a, 0) and µ1 > µ2 (s) The position of image may be in between the
position of object and centre of
curvature of interface.
6. Match the entries of Column I with entries of Column II for real point object O:
Column I Column II
(A) µ µ 2
(p) Number of images formed is 1
1
O µ µ3
1
mirror
(B) µ2 (q) Number of images formed is 2
µ1
Air µ3
O
µ4
Air
Air Air
O
Air Air
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RANK ENHANCEMENT SHEET GEOMETRICAL OPTICS JEE Advance
(D) Air
µ3 (s) Number of images formed is 4
µ1
µ4
O
µ4
Air
O C
1. A point source of source of light S is kept on the axis of a cone of B
radius r and height h as shown in the figure. The inner surface of
S
cone is made reflecting. Determine the minimum value semi-
vertical angle α in degrees of the cone for which the rays emitted α h
from source (S) on the axis of the cone will be reflected from
o
conical surface not more than once. Express answer as (α/10) . A
4. The xz plane is the boundary between two transparent medium. Medium –I with y ≥ 0 has
refractive index µ and medium –II with y ≤ 0 has a refractive index 1. A ray of light in medium-I,
given by vector n = ˆi − 3ˆj is incident on the plane of separation. If the reflected and refracted
rays make an angle of 90° with each other, then the value of µ is k . Find the value of k.
20 cm
7. There are two thin identical equiconvex lens of different refractive indices but of same radius of
curvature R = 60 cm put inside water close together. The focal length of combined lens is 30 cm
in water then find sum of refractive indices of two lens.
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RANK ENHANCEMENT SHEET GEOMETRICAL OPTICS JEE Advance
8. Find the value of x/4 (in cm) for which all the (paraxial) f = 10 cm R = 10 cm
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ANSWERS
1. C 2. B 3. A 4. A 5. C
6. A 7. A 8. A 9. C 10. C
11. C 12. D. 13. A 14. B 15. A
16. B 17. B 18. C 19. B 20. A
21. D 22. A 23. B 24. A
1. A, B 2. A, B, C 3. B, D 4. B, D 5. A, B, D
COMPREHENSION TYPE
1. B 2. A 3. C 4. B 5. A
6. C 7. D 8. A 9. D 10. A
11. A 12. B 13. C 14. B 15. D
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