RAY OPTICS - REFLECTION AND REFRACTION PREVIOUS YEARS BOARD QUESTIONS
Numerical problems
1. Monochromatic light of wavelength 589 nm incident from air on water surface. what are the values of wavelength, frequency and speed of (a) reflected light (b) refracted light.
Refractive index of water is 1.33.
2.The Apparent depth of an object at the bottom of a tank filled with a liquid of refractive index 1.3 is 7.7 cm. what is the actual depth of the liquid in the tank?
3.An object is kept in front of a concave mirror of focal length 20 cm. The image formed is 3 times the size of object. Calculate the possible distances of the object from the mirror.
4.Use mirror formula to show that for an object lying between F and 2F of a concave mirror, a real image is formed beyond 2F
5.Find the position of object, which when placed in front of a convex mirror of focal length 20 cm, produces virtual image, which is half the size of object
6.The radius of curvature of each surface of a convex lens of refractive index 1.5 is 40 cm. Calculate its power.
7. The radius of curvature of each face of a biconvex lens, made of glass of refractive index 1.5 is 30 cm. calculate the focal length of the lens in air.
8.Glass has a refractive index of 1.5. A convex lens made of thin glass has a focal length of 20 cm in air. It is immersed in water whose refractive index is 4/3. Calculate the apparent changed focal length of the lens.
9. A Double concave lens of glass of refractive index 1.5 has both radii of curvature of 40 cm. An object 2 cm high is placed at 10 cm from the lens. Find the position, nature and size of image
10. Two thin lenses of focal lengths +10 cm and -5 cm are kept in contact. what is the (a)focal length (b) power of combination.
11.A converging lens has a focal length of 20cm in air. It is made of material of refractive index 1.6. If it is immersed in a liquid of refractive index 1.3, what will be its new focal length? How does the nature of lens change if this lens is immersed in a liquid of refractive index 1.8?
12. A double convex lens made of glass of refractive index 1.6 has it's both surfaces of equal radii of curvature of 30 cm each.An object of 5 cm height is placed at a distance of 12.5 cm from the lens.Find the position, nature and size of image.
13. An illuminated object and a screen are placed 90 cm apart. Determine focal length and nature of lens required to produce a clear image on the screen, twice the size of the object.
14. A substance has Critical Angle of 45° for yellow light. What is the refractive index?
15.Use mirror equation to show that -
(a) A convex mirror always produces a virtual image independent of the location of object.
(b) An object placed between the pole and focus of a concave mirror produces a virtual and enlarged.
Download CBSE Class 12 Physics Previous Years Question Papers with Solutions
OPTICAL INSTRUMENTS- PREVIOUS YEARS BOARD QUESTIONS
1. A
converging lens of focal length 6.25 cm is used as a magnifying glass, if the
near point of the observer is 25 cm from the eye and the lens is held close to
the eye. Calculate
(i)
the distance of the object from
the lens and
(ii)
the
angular magnification.
2. A
compound microscope with an objective of 1.0 cm focal length and an eyepiece of
2.0 cm focal length, has a tube length of 20 cm. Calculate the magnifying power
of the microscope, if the final image is formed at the near point of the eye.
3. A
compound microscope uses an objective lens of focal length 4 cm and eye lens of
focal length 10 cm and object is placed at 6 cm from the objective lens
i) Calculate magnifying power of the compound
microscope if the final image is formed at the near point
ii) Calculate the length of the compound
microscope also .
4. The total
magnification produced by a compound microscope is 20, while that produced by
the eyepiece alone is 5. When the microscope is focused on a certain object ,the
distance between objective and eyepiece is 14 cm. Find the focal length of
objective and eyepiece, if distance of distinct vision is 20 cm.
5. The focal
lengths of the objective and eyepiece of a microscope are 1.25 cm and 5 cm
respectively. Find the position of the object related to the objective in order
to obtain an angular magnification of 30 in normal adjustment.
6. A small
telescope has an objective lens of focal length 150 cm and an eyepiece of focal
length 5 cm. If this telescope is used to view 100m high tower 3 km away. Find the
height of the final image, when it is formed 25 cm away from the eyepiece.
7. A small
telescope has an objective lens of focal length 150 cm and eyepiece of focal
length 5 cm. What is the magnifying power of the telescope for viewing distant
objects in normal adjustment.
8. The sum
of focal length of two lenses of a refracting telescope is 105 cm, the focal length of 1 lens is 20
times that of the other. Determine the total magnification of the telescope
when the final image is formed at infinity.
9. The focal
length of objective of an astronomical telescope is 1.0 m. If the magnifying
power of the telescope is 20, find the focal length of the eyepiece and the
length of the telescope for the relaxed eye .
3 Comments
please give the answers
ReplyDeletei want solutions of all the questions which mention above
ReplyDeleteAnswers please
ReplyDelete