JEE Questions for Physics Ray Optics Quiz 20 - MCQExams.com

The refracting angle of prism is A and refractive index of material of prism is cot A/2. The angle of minimumdeviation is
  • 180°– 3A
  • 180° + 2A
  • 90°– A
  • 180° – 2A
An isosceles prism of angle 120° has a refractive index of 1.44. Two parallel monochromatic rays enter the prism parallel to each other in air as shown. The rays emerging from the opposite faces
Physics-Ray Optics-86428.png
  • Are parallel to each other
  • Are diverging
  • Make an angle 2 sin–1 (0.with each other
  • Make an angle 2{sin–1 (0.72)–30°} with each other
A ray of light is incident on the hypotenuse of a right-angled prism after travelling parallel to the base inside the prism. Ifµ is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from thehypotenuse is

  • Physics-Ray Optics-86430.png
  • 2)
    Physics-Ray Optics-86431.png

  • Physics-Ray Optics-86432.png

  • Physics-Ray Optics-86433.png
A plano-convex lens when silvered in the plane side behaves like a concave mirror of focal length 30cm. However, when silvered on the convex side it behaves like a concave mirror of focal length 10 cm. Then the refractive index of its material will be
  • 3.0
  • 2.0
  • 2.5
  • 1.5
A car is fitted with a convex side-view mirror of focal length 20cm. A second car 2.8m behind the first car is overtaking the first car at a relative speed of 15m/s. The speed of the image of the second car as seen in themirror of the first one is

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  • 2)
    Physics-Ray Optics-86437.png

  • Physics-Ray Optics-86438.png

  • Physics-Ray Optics-86439.png
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/s2]
  • 9 m/s
  • 12 m/s
  • 16 m/s
  • 21.33 m/s
A small source of light is to be suspended directly above the centre of a circular table of radius R. What should be the height of the light source above the table so that the intensity of light is maximum at the edges of the table compared to any other height of the source

  • Physics-Ray Optics-86442.png
  • 2)
    Physics-Ray Optics-86443.png
  • R

  • Physics-Ray Optics-86444.png
Two point light sources are 24 cm apart. Where should a convex lens of focal length 9 cm be put in between them from one source so that the images of both the sources are formed at the same place
  • 6 cm
  • 9 cm
  • 12 cm
  • 15 cm
A light source is located at P1 as shown in the figure. All sides of the polygon are equal. The intensity of illumination at P2 is I0. What will be the intensity of illumination at P3
Physics-Ray Optics-86446.png

  • Physics-Ray Optics-86447.png
  • 2)
    Physics-Ray Optics-86448.png

  • Physics-Ray Optics-86449.png

  • Physics-Ray Optics-86450.png
A container is filled with water (μ = 1.upto a height of 33.25 cm. A concave mirror is placed 15 cm above the water level and the image of an object placed at the bottom is formed 25 cm below the water level. Thefocal length of the mirror is
Physics-Ray Optics-86452.png
  • 10
  • 15
  • 20
  • 25
A point object is moving on the principal axis of a concave mirror of focal length 24cm towards the mirror. When it is at a distance of 60cm from the mirror, its velocity is 9cm / sec. What is the velocity of the image at that instant
  • 5 cm / sec towards the mirror
  • 4 cm / sec towards the mirror
  • 4 cm / sec away from the mirror
  • 9 cm / sec away from the mirror
A concave mirror is placed on a horizontal table with its axis directed vertically upwards. Let Obe the pole of the mirror and C its centre of curvature. A point object is placed at C. It has a real image, also located at C. If the mirror is now filled with water, the image will be
  • Real, and will remain at C
  • Real, and located at a point between C and ∞
  • Virtual and located at a point between C and O
  • Real, and located at a point between C and O
The diameter of moon is 3.5 × 103 km and its distance from the earth is 3.8 × 105 km. If it is seen through atelescope whose focal length for objective and eye lens are 4 m and 10 cm respectively, then the angle subtended by the moon on the eye will be approximately
  • 15°
  • 21°
  • 30°
  • 35°
The focal length of an objective of a telescope is 3 metre and diameter 15 cm. Assuming for a normal eye, the diameter of the pupil is 3 mm for its complete use, the focal length of eye piece must be
  • 6 cm
  • 6.3 cm
  • 20 cm
  • 60 cm
A convex lens of focal length 30 cm and a concave lens of 10 cm focal length are placed so as to have the same axis. If a parallel beam of light falling on convex lens leaves concave lens as a parallel beam, then the distance between two lenses will be
  • 40 cm
  • 30 cm
  • 20 cm
  • 10 cm
A small plane mirror placed at the centre of a spherical screen of radius R. A beam of light is falling on the mirror. If the mirror makes n revolution per second, the speed of light on the screen after reflection from the mirror will be
  • 4πnR
  • 2πnR

  • Physics-Ray Optics-86459.png

  • Physics-Ray Optics-86460.png
A room (cubical) is made of mirrors. An insect is moving along the diagonal on the floor such that the velocity of image of insect on two adjacent wall mirrors is 10 cms–1. The velocity of image of insect in ceiling mirror is
  • 10 cms–1
  • 20 cms–1

  • Physics-Ray Optics-86462.png

  • Physics-Ray Optics-86463.png
Figure shows a cubical room ABCD with the wall CD as a plane mirror. Each side of the room is 3m. We place a camera at the midpoint of the wall AB. At what distance should the camera be focused to photograph an object placed at A
Physics-Ray Optics-86465.png
  • 1.5m
  • 3m
  • 6m
  • More than 6m
If an object moves towards a plane mirror with a speed v at an angle θ to the perpendicular to the plane of the mirror, find the relative velocity between the object and the image
Physics-Ray Optics-86467.png
  • v
  • 2v
  • 2v cos θ
  • 2v sin θ
A plane mirror is placed at the bottom of the tank containing a liquid of refractive index μ. P is a smallobject at a height h above the mirror. An observer O–vertically above P outside the liquid see P and its image in the mirror. The apparent distance between these two will be
Physics-Ray Optics-86469.png

  • Physics-Ray Optics-86470.png
  • 2)
    Physics-Ray Optics-86471.png

  • Physics-Ray Optics-86472.png

  • Physics-Ray Optics-86473.png
One side of a glass slab is silvered as shown. A ray of light is incident on the other side at angle of incidence i = 45°. Refractive index of glass is given as 1.5. The deviation of the ray of light from its initial path when it comes out of the slab is
Physics-Ray Optics-86475.png
  • 90°
  • 180°
  • 120°
  • 45°

Physics-Ray Optics-86477.png
  • 15 cm
  • 12.5 cm
  • 7.5 cm
  • 10 cm
In an experiment to determine the focal length (f)of a concave mirror by the u – v method, a student places the object pin A on the principal axis at a distance x from the pole P. The student looks at the pin and its inverted image from a distance keeping his/her eye in line with PA . When the student shifts his/her eye towards left, the image appears to the right of the object pin. Then
  • x
  • f< x<2f
  • x = 2f
  • x > 2f
Two transparent slabs have the same thickness as shown. One is made of material A of refractive index 1.5. The other is made of two materials B and C with thickness in the ratio 1 : 2. The refractive index of C is 1.6. If a monochromatic parallel beam passing through the slabs has the same number of waves inside both, the refractive index of B is
Physics-Ray Optics-86479.png
  • 1.1
  • 1.2
  • 1.3
  • 1.4
An object is placed infront of a convex mirror at a distance of 50 cm. A plane mirror is introduced covering the lower half of the convex mirror. If the distance between the object and plane mirror is 30 cm, it is found that there is no parallax between the images formed by two mirrors. Radius of curvature of mirror will be
  • 12.5 cm
  • 25 cm
  • 50/3 cm
  • 18 cm
A cube of side 2 m is placed in front of a concave mirror focal length 1 m with its face P at a distance of 3 m and face Q at a distance of 5 m from the mirror. The distance between the images of face P and Q and height of images of P and Q are
Physics-Ray Optics-86482.png
  • 1 m, 0.5 m, 0.25 m
  • 0.5 m, 1 m, 0.25 m
  • 0.5 m, 0.25 m, 1 m
  • 0.25 m, 1 m, 0.5 m
A small piece of wire bent into an L shape with upright and horizontal portions of equal lengths, is placed with the horizontal portion along the axis of the concave mirror whose radius of curvature is 10 cm. If the bend is 20 cm from the pole of the mirror, then the ratio of the lengths of the images of the upright and horizontal portions of the wire is
  • 1 : 2
  • 3 : 1
  • 1 : 3
  • 2 : 1
The image of point P when viewed from top of the slabs will be
Physics-Ray Optics-86485.png
  • 2.0 cm above P
  • 1.5 cm above P
  • 2.0 cm below P
  • 1 cm above P
A fish rising vertically up towards 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
Physics-Ray Optics-86487.png
  • 4.5 ms–1
  • 5 ms–1
  • 3.0 ms–1
  • 3.4 ms–1
A beaker containing liquid is placed on a table, underneath a microscope which can be moved along a vertical scale. The microscope is focused, through the liquid onto a mark on the table when the reading on the scale is a. It is next focused on the upper surface of the liquid and the reading is b. More liquid is added and the observations are repeated, the corresponding readings are c and d. The refractive index of the liquid is

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  • 2)
    Physics-Ray Optics-86490.png

  • Physics-Ray Optics-86491.png

  • Physics-Ray Optics-86492.png
There is an equiconvex glass lens with radius of each face as R and aμ g = 3/2 and aμ w = 4/3. If there iswater in object space and air in image space, then the focal length is
  • 2R
  • R
  • 3 R/2
  • R2
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
Physics-Ray Optics-86496.png
  • 176°
  • 4°
  • 178°
  • 2°
An optical fibre consists of core of μ1 surrounded by a cladding of μ2<μ1. A beam of light enters from air at an angle α with axis of fibre. The highest α for which ray can be travelled through fibre is
Physics-Ray Optics-86498.png

  • Physics-Ray Optics-86499.png
  • 2)
    Physics-Ray Optics-86500.png

  • Physics-Ray Optics-86501.png

  • Physics-Ray Optics-86502.png
A rod of glass (μ = 1.and of square cross section is bent into the shape shown in the figure. A parallel beam of light falls on the plane flat surface A as shown in the figure. If d is the width of a side and R is the radius of circular arc then for what maximum value ofd/Rlight entering the glass slab through surface A emerges from the glass through B
Physics-Ray Optics-86504.png
  • 1.5
  • 0.5
  • 1.3
  • None of these
The slab of a material of refractive index 2 shown in figure has curved surface APB of radius of curvature 10 cm and a plane surface CD. On the left of APB is air and on the right of CD is water with refractive indices as given in figure. An object Ois placed at a distance of 15 cm from pole P as shown. The distance of the final image of Ofrom P, as viewed from the left is
Physics-Ray Optics-86506.png
  • 20 cm
  • 30 cm
  • 40 cm
  • 50 cm
A double convex lens, lens made of a material of refractive index μ1, placed inside two liquids or refractive indices μ2 and μ3, as shown. μ2>μ1>μ3. A wide, parallel beam of light is incident on the lens from the left. The lens will give rise to
Physics-Ray Optics-86508.png
  • A single convergent beam
  • Two different convergent beams
  • Two different divergent beams
  • A convergent and a divergent beam
The distance between a convex lens and a plane mirror is 10 cm. The parallel rays incident on the convex lens after reflection from the mirror form image at the optical centre of the lens. Focal length of lens will be
Physics-Ray Optics-86510.png
  • 10 cm
  • 20 cm
  • 30 cm
  • Cannot be determined
A compound microscope is used to enlarge an object kept at a distance 0.03m from it\'s objective which consists of several convex lenses in contact and has focal length 0.02m. If a lens of focal length 0.1m is removed from the objective, then by what distance the eye-piece of the microscope must be moved to refocus the image
  • 2.5 cm
  • 6 cm
  • 15 cm
  • 9 cm
If the focal length of the objective lens and the eye lens are 4 mm and 25 mm respectively in a compound microscope. The length of the tube is 16 cm. Find its magnifying power for relaxed eye position
  • 32.75
  • 327.5
  • 0.3275
  • None of these
Three right angled prisms of refractive indices n1, n2 and n3 are fixed together using an optical glue as shown in figure. If a ray passes through the prisms without suffering any deviation, then
Physics-Ray Optics-86514.png
  • n1 = n2 = n3
  • n1 = n2 ≠ n3
  • 1 + n1 = n2 + n3

  • Physics-Ray Optics-86515.png
In a compound microscope, the focal length of the objective and the eye lens are 2.5 cm and 5 cm respectively. An object is placed at 3.75 cm before the objective and image is formed at the least distance of distinct vision, then the distance between two lenses will be (i.e., length of the microscopic tube)
  • 11.67 cm
  • 12.67 cm
  • 13.00 cm
  • 12.00 cm
In a grease spot photometer light from a lamp with dirty chimney is exactly balanced by a point source distance 10 cm from the grease spot. On clearing the chimney, the point source is moved 2 cm to obtain balance again. The percentage of light absorbed by dirty chimney is nearly
  • 56%
  • 44%
  • 36%
  • 64%
The separation between the screen and a plane mirror is 2r. An isotropic point source of light is placed exactly midway between the mirror and the screen. Assume that mirror reflects 100% of incident light. Then the ratio of illuminances on the screen with and without the mirror is
  • 10 : 1
  • 2 : 1
  • 10 : 9
  • 9 : 1
The separation between the screen and a concave mirror is 2r. An isotropic point source of light is placed exactly midway between the mirror and the screen. Mirror has a radius of curvature r and reflects 100% of the incident light. Then the ratio of illuminances on the screen with and without the mirror is
  • 10 : 1
  • 2 : 1
  • 10 : 9
  • 9 : 1
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-86521.png
  • 60 cm left of AB
  • 30 cm left of AB
  • 12 cm left of AB
  • 60 cm right of AB
A bi-convex lens of focal length f forms a circular image of sun of radius r in focal plane. Then

  • Physics-Ray Optics-86523.png
  • 2)
    Physics-Ray Optics-86524.png

  • Physics-Ray Optics-86525.png
  • If f is doubled, intensity will increase
The image of a small electric bulb fixed on the wall of a room is to be obtained on the opposite wall 4m away by means of a large convex lens. The maximum possible focal length of the lens required for this purpose will be
  • 0.5 m
  • 1.0 m
  • 1.5 m
  • 2.0 m
A light bulb is at a depth of D below the surface of water. An opaque disc of radius R is placed on the surface of water just above the bulb. The bulb is not at all seen through the surface of water, then (n = Refractive index of water)

  • Physics-Ray Optics-86528.png
  • 2)
    Physics-Ray Optics-86529.png

  • Physics-Ray Optics-86530.png

  • Physics-Ray Optics-86531.png
As the position of an object (u) reflected from a concave mirror is varied, the position of the image (v) also varies. By letting the u changes from 0 to + ∞ the graphbetween v versus u will be

  • Physics-Ray Optics-86533.png
  • 2)
    Physics-Ray Optics-86534.png

  • Physics-Ray Optics-86535.png

  • Physics-Ray Optics-86536.png
When light is incident on a medium at angle i and refracted into a second medium at an angle r, the graph of sin i vs sin r is as shown in the graph. From this, one can conclude that
Physics-Ray Optics-86538.png
  • Velocity of light in the second medium is 1.73 times the velocity of light in the I medium
  • Velocity of light in the I medium is 1.73 times the velocity in the II medium

  • Physics-Ray Optics-86539.png

  • Physics-Ray Optics-86540.png
0:0:1


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