A concave mirror of focal length f produces an image n times the size of the object. If the image is real then the distance of the object from the mirror is
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4.
A ray of light passes through four transparent media with refractive indices as shown in the figure. The surface of all media are parallel. If the emergent ray CD is parallel to the incident ray AB, then
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Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index is placed on face AC of the prism. The prism is made of glass of refractive index 3/2. The limits of for which total internal reflection cannot take place on face AC is -
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We have two equilateral prisms A and B. They are made of materials having refractive index 1.5 and 1.6. For minimum deviation, incident angle will be
1. small for prism A
2. small for prism B
3. equal for both the prisms
4. can’t be predicted
A thin plano-convex glass lens ( = 1.5) has its plane surface silvered and R is the radius of curvature of curved part, then which of the following ray diagram is true for an object placed at O?
A thin convergent glass lens ( = 1.5) has a power of +5.0 D. When this lens is immersed in a liquid of refractive index ml, it acts as a divergent lens of focal length 100 cm. The value of ml is
1. 4/3
2. 5/3
3. 5/4
4. 6/5
A microscope has an objective of focal length 1.5 cm and an eye –piece of focal length 2.5 cm. If the distance between objective and eye-piece is 25 cm, what is the approximate value of magnification produced for relaxed eye?
1. 75
2. 110
3. 140
4. 25
A circular beam of light of diameter d = 2 cm falls on a plane surface of glass. The angle of incidence is 600 and refractive index of glass is = 3/2. The diameter of the refracted beam is
1. 4.0 cm
2. 3.0 cm
3. 3.26 cm
4. 2.52 cm
The distance between an object and the screen is 100 cm. A lens produces an image on the screen when placed at either of the positions 40 cm apart. The power of the lens is nearly
1. 3 dioptres
2. 5 dioptres
3. 7 dioptres
4. 9 dioptres
A light ray is incident upon a prism in minimum deviation position and suffers a deviation of 34°. If the shaded half of the prism is knocked off, the ray will
1. Suffer a deviation of 34°
2. Suffer a deviation of 68°
3. Suffer a deviation of 17°
4. Not come out of the prism
The light ray is incidence at angle of 60° on a prism of angle 45°. When the light ray falls on the other surface at 90°, the refractive index of the material of prism and the angle of deviation are given by
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A ray of light falls on the surface of a spherical glass paper weight making an angle with the normal and is refracted in the medium at an angle . The angle of deviation of the emergent ray from the direction of the incident ray is
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An observer can see through a pinhole the top end of a thin rod of height h, placed as shown in the figure. The beaker height is 3h and its radius h. When the beaker is filled with a liquid upto a height 2h, he can see the lower end of the rod. Then the refractive index of the liquid is
1. 5/2
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3.
4. 3/2
A point object is moving along the principle axis of a concave mirror at rest of focal length 30cm with speed 5m/s towards the mirror. Find the speed of image of object when object is at a distance 60cm from mirror.
1. 5m/s away from mirror
2. 5m/s towards the mirror
3. 10m/s away from mirror
4. 10m/s towards the mirror
In the given situation, for what value of i, the incidence ray will retrace its initial path
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