JEE Questions for Physics Ray Optics Quiz 4 - MCQExams.com

The refractive index of water, glass and diamond are 1.33, 1.50, 2.40 respectively. The refractive index of diamond relative to water and of glass relative to diamond, respectively are nearly
  • 1.80, 0.625
  • 0.554, 0.625
  • 1.12, 1.8
  • 0.554, 1.6
A ray of light on the surface of a glass plate of thickness t. If the angle of incidence θ is small, the emerging ray would be displaced side ways by an amount
(take, n = refractive index of glass)
  • t θ n/(n + 1)
  • t θ (n – 1)/n
  • t θ n/(n – 1)
  • t θ (n + 1)/n
A parallel beam of light is incident on a solid transparent sphere of a material of refractive index n. If a point image is produced at the back of the sphere, the refractive index of the material of sphere is
  • 2.5
  • 1.5
  • 1.25
  • 2.0
The wavelength of a certain colour in air is 600 nm. What is the wavelength and speed of this colour in glass of refractive index 1.5 ?
  • 500 nm and 2 × 1010 cms-1
  • 400 nm and 2 × 108 cms-1
  • 300 nm and 3 × 109 cms-1
  • 700 nm and 1.5 × 109 cms-1
A wave has velocity u in medium P and velocity 2u in medium Q. If the wave is incident in medium P at an angle 30°, then the angle of refraction will be
  • 30°
  • 45°
  • 60°
  • 90°
A fish, looking up through the water sees the outside world contained in a circular horizon. If the refractive index of water is 4/3 and the fish is 12 cm below the surface of water, the radius of the circle in centimetre is

  • Physics-Ray Optics-85435.png
  • 2)
    Physics-Ray Optics-85436.png

  • Physics-Ray Optics-85437.png

  • Physics-Ray Optics-85438.png
A thin convex lens made from crown glass (μ = 3/has focal length f. When it is measured in two different liquids having refractive indices 4/3 and 5/3. lt has the focal lengths f1 and f2 , respectively. The correct relation between the focal length is
  • f1 = f2 < f
  • f1 > f and f2 becomes negative
  • f2 > f and f1 becomes negative
  • f1 and f2 both become negative.
A point object is placed at a distance of 20 cm from a thin plano-convex lens of focal length 15 cm, if the plane surface is silvered. The image will form at
Physics-Ray Optics-85439.png
  • 60 cm left of AB
  • 30 cm left of AB
  • 12 cm left of AB
  • 60 cm right of AB
A biconvex lens of focal length f forms a circular image of sun of radius r in focal plane. Then,
  • πr 2 ∝ f
  • πr 2 ∝ f 2
  • if lower half part is covered by black sheet, then area of the image is equal to are π2/2
  • if f is doubled, intensity will increase.
Graph of position of image versus position of point object from a convex lens is shown. Then, focal length of the lens is
Physics-Ray Optics-85440.png
  • 0.50 ± 0.05 cm
  • 0.50 ± 0.10 cm
  • 5.00 ± 0.05 cm
  • 5.00 ± 0.1 0 cm
A luminous object is separated from a screen by distance d. A convex lens is placed between the object and the screen such that it forms a distinct image on the screen. The maximum possible focal length of this convex lens is
  • 4d
  • 2d
  • d / 2
  • d / 4
Figure shows an object AB placed in front of two thin coaxial lenses 1 and 2 with focal lengths 24 cm and 9.0 cm, respectively. The object is 6.0 cm, from the lens I and the lens separation is L=10 cm. Where does the system of two lenses produce an image of the object AB ?
Physics-Ray Optics-85441.png
  • + 18 cm
  • – 18 cm
  • + 24 cm
  • – 24 cm
A convex lens has its radii of curvature equal. The focal length of the lens is f. If it is divided vertically into two identical plano-convex lenses by cutting it, then the focal length of the plano-convex lens is (μ = the refractive index of the material of the lens)
  • f
  • f / 2
  • 2 f
  • ( μ–1 ) f
A thin converging lens of focal length f = 25 cm forms the image of an object on a screen placed at a distance of 75 cm from the lens. The screen is moved closer to the lens by a distance of 25 cm. The distance through which the object has to be shifted, so that its image on the screen in sharp again is
  • 37.5 cm
  • 16.25 cm
  • 12.5 cm
  • 13.5 cm
A double convex lens of glass of refraction index µ is immersed in a medium of refractive index µ1 . If a parallel beam emerges undeviated through the lens, then
  • µ = µ1
  • 2)
    Physics-Ray Optics-85442.png
  • µ > µ1
  • µ < µ1
Light form a point source in air falls on a spherical glass surface (n = 1.67 and radius of curvature = 25 cm). The distance of the light source from the glass surface is 95 cm. At what position, the image is formed?
  • 75.45 cm
  • 90.50 cm
  • 105.25 cm
  • 99.40 cm
The image of an object, formed by a plano-convex lens at a distance of 8 m behind the lens, is real and in one-third the size of the object. The wavelength of light inside the lens is 2/3 times the wavelength in free space. The radius of the curved surface of the lens is
  • 1 m
  • 2 m
  • 3 m
  • 6 m
Diameter of a plano-convex lens is 6 cm and thickness at the centre is 3 cm. If speed of light in material of lens is 2 × 108 m/s, the focal length of the lens is
  • 15 cm
  • 20 cm
  • 30 cm
  • 10 cm
The graph between angle of deviation (δ) and angle of incidence (i) for a triangular prism is represented by

  • Physics-Ray Optics-85444.png
  • 2)
    Physics-Ray Optics-85445.png

  • Physics-Ray Optics-85446.png

  • Physics-Ray Optics-85447.png
The plane faces of two identical plano-convex lenses each having a focal length of 50 cm are placed against each ether to form a usual biconvex lens. The distance from this lens combination at which an object must be placed to obtain a real, inverted image which has the same size as the object is
  • 50 cm
  • 25 cm
  • 100 cm
  • 40 cm
Luminous flux and luminous intensity are related as

  • Physics-Ray Optics-85495.png
  • 2)
    Physics-Ray Optics-85496.png

  • Physics-Ray Optics-85497.png

  • Physics-Ray Optics-85498.png
The plane face of a planoconvex lens is silvered. If μ be the refractive index and R, the radius of curvature of curved surface, then the system will behave like a concave mirror of radius of curvature
  • μ R
  • 2)
    Physics-Ray Optics-85449.png

  • Physics-Ray Optics-85450.png

  • Physics-Ray Optics-85451.png
The relation between n1 and n2, if behaviour of light ray is as shown in figure is
Physics-Ray Optics-85452.png
  • n1 >> n2
  • n2 > n1
  • n1 > n2
  • n1 = n2
An object 2.4 m in front of a lens forms a sharp image on a film 12 cm behind the lens. A glass plate 1 cm thick, of refractive index 1.50 is interposed between lens and film with its plane faces parallel to film. At what distance (from lens) should object shifted to be in sharp focus on film?
  • 7.2 m
  • 2.4 m
  • 3.2 m
  • 5.6 m
A thin lens of focal length + 12 cm is immersed in water. What is its new focal length? (Refractive index of glass = 1.5, refractive index of water = 1.
  • 16 cm
  • 48 cm
  • 36 cm
  • 40 cm

Physics-Ray Optics-85455.png
  • 4, 5
  • 3, 6
  • 2, 7
  • 1, 8
The focal length of the lens of refractive index (μ = 1.in air is 10 cm. If air is replaced by water of µ = 4/3, its focal length is
  • 20 cm
  • 30 cm
  • 40 cm
  • 25 cm
  • 35 cm
Refractive index of the material of a prism is 1.5. If δm = A, what will be a value of angle of the given prism?
(where, δm = minimum deviation; A = angle of prism)
  • 82.8°
  • 41.4°
  • 48.6°
  • 90°
A transparent plastic bag filled with air forms a concave lens. Now, if this bag is completely immersed in water, then it behaves as
  • divergent lens
  • convergent lens
  • equilateral prism
  • rectangular slab
Given figures show the arrangements of two lenses. The radii of curvature of all the curved surfaces are same. The ratio of the equivalent focal length of combinations P, Q and R is
Physics-Ray Optics-85456.png
  • 1: 1:1
  • 1:1: -1
  • 2 :1:1
  • 2 :1: 2
A biconvex lens of focal length 15 cm is in front of a plane mirror. The distance between the lens and the mirror is 10 cm. A small object is kept at a distance of 30 cm from the lens. The final image is
  • virtual and at a distance of 16 cm from the mirror
  • real and at a distance of 16 cm from the mirror
  • virtual and at a distance of 20 cm from the mirror
  • None of the above

Physics-Ray Optics-85457.png
  • 6
  • 7
  • 8
  • 9
Two beams of red and violet colours are made to pass separately through a prism of A = 60°. In the minimum deviation position, the angle of refraction inside the prism will be
  • greater for red colour
  • equal but not 30° for both the colours
  • greater for violet colour
  • 30° for both the colours.
A converging lens is to project the image of a lamp 4 times the size of the lamp on a wall at a distance of 10 m from the lamp. The focal length of the lens is
  • 1.6 m
  • 2.67 m
  • 4.4 m
  • – 1.6 m
In an optics experiments, with the position of the object fixed, a student varies the position of a convex lens and for each position, the screen is adjusted to get a clear image of the object. A graph between the object distance u and the image distance v, from the lens, is plotted using the same scale for the two axes. A straight line passing through the origin and making an angle of 45° with the x-axis meets the experimental curve at P. The coordinates of P will be
  • ( 2 f , 2 f )
  • 2)
    Physics-Ray Optics-85459.png
  • ( f , f )
  • ( 4 f , 4 f )
Assertion (A) Angle of deviation depends on the angle of prism.
Reason (R) For thin prism δ = (μ –1)A
where, δ = angle of deviation, μ = refractive index and A = angle of prism
  • Both A and R are correct and R is the correct explanation of A
  • Both A and R are correct and R is not the correct explanation of A
  • A is correct but R is incorrect
  • A is incorrect but R is correct.
The angle of minimum deviation for an incident light ray on an equilateral prism is equal to its refracting angle. The refractive index of its material is

  • Physics-Ray Optics-85460.png
  • 2)
    Physics-Ray Optics-85461.png

  • Physics-Ray Optics-85462.png

  • Physics-Ray Optics-85463.png
Two plano-concave lenses (1 andof glass of refractive index 1.5 have radii of curvature 25 cm and 20 cm. They are placed in contact with their curved surfaces towards each other and the space between them is filled with liquid of refractive index 4/3. Then, the combination is
Physics-Ray Optics-85464.png
  • convex of focal length 70 cm
  • concave of focal length 70 cm
  • concave of focal length 66.6 cm
  • convex of focal length 66.6 cm
  • concave of focal length 72.5 cm
A thin prism P of refracting angle 3° and refractive index 1.5 is combined with another thin prism Q of refractive index 1.6 to produce dispersion without deviation. Then, the angle of prism is
  • 3°
  • 4°
  • 3.5°
  • 2.5°
  • 5°
A ray of light passes through an equilateral prism such that the angle of incidence is equal to the angle of emergence and the latter is equal to 3/4 the angle of prism. The angle of deviation is
  • 25°
  • 30°
  • 45°
  • 35°
Convex lens made up of glass (μg = 1.and radius of curvature R is dipped into water. Its focal length will be
(Refractive index of water = 4 /
  • 4R
  • 2R
  • R
  • R / 2
A beam of light consisting of red, green and blue colours is incident on a right-angled prism ABC. The refractive indices of the material of the prism for the above red, green and blue wavelengths are 1.39, 1.44 and 1.47, respectively. colour/colours transmitted through the face AC of the prism will he
Physics-Ray Optics-85466.png
  • red only
  • red and green
  • All the three
  • None of these
Two beams of red and violet colours are made to pass separately through a prism (angle of the prism is 60°). In the position of minimum deviation, the angle of refraction will he
  • 30° for both the colours
  • greater for the violet colour
  • greater for the red colour
  • equal but not 30° for both the colours
A student measures the focal length of a convex lens by putting an object pin at a distance u front the lens and measuring the distance v of the image pin. The graph between u and v plotted by the student should look like

  • Physics-Ray Optics-85467.png
  • 2)
    Physics-Ray Optics-85468.png

  • Physics-Ray Optics-85469.png

  • Physics-Ray Optics-85470.png
A ray falls on a prism ABC (AB =BC) and travels as shown in figure. The minimum refractive of the prism material should be
Physics-Ray Optics-85471.png
  • 4/3
  • √2
  • 1.5
  • √3
Figure shows a mixture of blue, green and red coloured rays incident normally on a right angled prism. The critical angles of the material of the prism for red, green and blue are 46°, 44° and 43°, respectively. The arrangement will separate
Physics-Ray Optics-85472.png
  • red colour from blue and green
  • blue colour from red and green
  • green colour from red and blue
  • all the three colours
A convex lens is made of 3 layers of glass of 3 different materials as in the figure. A point object is placed on its axis. The number of images of the object are
Physics-Ray Optics-85473.png
  • 1
  • 2
  • 3
  • 4
If the angle of minimum deviation is of 60° for an equilateral prism, then the refractive index of the material of the prism is
  • 1.41
  • 1.5
  • 1.6
  • 1.33
  • 1.73
The radius of curvature of the convex face of a planoconvex lens is 15 cm and the refractive index of the material is 1.4. Then, the power of the lens in diopter is
  • 1.6
  • 1.66
  • 2.6
  • 2.66
  • 1.4
A lens made of glass whose index of refraction is 1.60 has a focal length of + 20 cm in air. Its focal length in water, whose refractive index is 1.33, will be
  • three times longer than in air
  • two times longer than in air
  • same as in air
  • None of the above
0:0:1


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