Some important question of physics 10th Class
Question 1. Name the phenomenon which is responsible for the twinkling of stars.
Question 2. Name the part of the human eye that helps in changing the focal length of the eye lens.
Question 3. Why do the stars appear higher than their actual position?
Question 4. Name the component of white light which deviates (i) the least and (ii) the most while passing through a glass prism.
Question 5. Name the defect of vision in which the eye loses its power of accommodation due to old age.
Question 6. Find the radius of curvature of a convex mirror having a focal length equal to 25 cm.
Question 7. Why does the clear sky appear blue? How would the sky appear in the absence of the earth‟s atmosphere?
Question 8. Draw a ray diagram to show the path of the reflected ray corresponding to an incident ray which is directed parallel to the principal axis of a convex mirror. Mark on it the angle of incidence and the angle of reflection.
Question 9. What is ozone? How does it protect the organisms on the Earth?
Question 10. (a) State the range of vision of a normal human eye.
(b) How do the ciliary muscles of a human eye help in the normal functioning of an eye?
Question 11. Why does the sun appear red during sunrise and sunset?
Question 12. A concave mirror produces three times magnified the real image of an object at 10 cm in front of it. Where is the image located?
Question 13. State the laws of refraction of light. If the speed of light in a vacuum is 3×108 ms−1. Find the speed of light in a medium of absolute refractive index 1.5.
Question 14. Mention the types of minor used as (i) rearview mirror, (ii) shaving mirrors. Give a suitable reason to justify your answer in each case.
Question 15. A spherical mirror produces an image of magnification −1 on a screen placed at a distance of 40 cm from the mirror:
(i) Write the type of mirror.
(ii) What is the nature of the image formed?
(iii) How far is the object located from the mirror?
(iv) Draw the ray diagram to show the image formation in this case.
Question 16. Why does the sun seem to rise two minutes before the actual sunrise and set two minutes after the actual sunset? Explain with the help of a labeled diagram.
Question 17. (a) What is meant by fossil fuel?
(b) Which fossil fuel is usually conserved when we save on electricity?
(c) At the present rate of consumption, how long will the known reserves of coal and petroleum last?
Question 18. Why does it take some time to see the objects in a dim room when you enter the room from bright sunshine outside?
Question 19. (a) Draw the ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed:
(i) at 2F1 (ii) between F1 and 2F1 of a lens.
(b) The image of a candle flame placed at a distance of 30 cm from a spherical lens is formed on a screen placed on the other side of the lens at a distance of 30 cm from the lens. Identify the type of lens and write its focal length what will be the nature of the image formed if the candle flame is shifted 20 cm towards the lens. Draw a ray diagram to justify your answer.
Question 20. (a) With the help of ray diagrams, show the formation of an image by
(i) a hypermetropic eye and
(ii) correction of hypermetropia by using an appropriate lens.
(b) The near point of a person suffering from hypermetropia is at 50 cm from his eye. What is the power of the lens needed to correct this defect? (near point of the normal eye is 25cm)
(c) What might be the possible reasons for the Hypermetropia?
Question 21. A student has obtained an image of a distant object on a screen to determine the focal length F1 of the given lens. His teacher after checking the image gave him another lens of focal length F2 and asked to focus the same object on the same screen. The student found that to obtain a sharp image he has to move the lens away from the screen. From this finding, we may conclude that both the lenses given to the student weres:t
(a) Concave and F1 < F2
(b) Convex and F1 < F2
(c) Convex and F1 > F2
(d) Concave and F1 > F2
Question 22. Hypermetropia is a defect of vision with which a person can see the distant objects clearly but is unable to see the nearby objects distinctly. This defect might be caused due to which of the following reasons: (i) Eyeball being too short.
(ii) A short focal length of the eye lens.
(iii) The eyeball is too long.
(iv) The large focal length of the eye lens. Choose the correct option among the following:
(a)i and ii
(b) ii and iii
(c) i and iv
(d) iii and iv
Question 23. In an experiment to trace the path of a ray of light through a glass prism for different values of angle of incidence a student would find that the emergent ray in each case:
(a) Is parallel to the incident ray
(b) Is perpendicular to the incident ray
(c) Is parallel to the refracted ray
(d) Bends at an angle to the direction of the incident ray
Question 24. On the basis of their experiment, “To trace the path of a ray of light through a rectangular glass slab,” students of a class arrived at which one of the following conclusions:
(a) The angle of incidence is greater than the angle of emergence,
(b) The angle of emergence is smaller than the angle of refraction,
(c) Emergent ray is parallel to the refracted ray,
(d) Incident ray and emergent ray are parallel to each other.
Question 25. A student obtains a blurred image of an object on a screen by using a concave mirror. In order to obtain a sharp image on the screen, he will have to shift the mirror
(a) Towards the screen
(b) Away from the screen
(c) Either towards or away from the screen depending upon the position of the object.
(d) To a position very far away from the screen.
{IMPORTANT SCIENCE QUESTION}
Question 2. Name the part of the human eye that helps in changing the focal length of the eye lens.
Question 3. Why do the stars appear higher than their actual position?
Question 4. Name the component of white light which deviates (i) the least and (ii) the most while passing through a glass prism.
Question 5. Name the defect of vision in which the eye loses its power of accommodation due to old age.
Question 6. Find the radius of curvature of a convex mirror having a focal length equal to 25 cm.
Question 7. Why does the clear sky appear blue? How would the sky appear in the absence of the earth‟s atmosphere?
Question 8. Draw a ray diagram to show the path of the reflected ray corresponding to an incident ray which is directed parallel to the principal axis of a convex mirror. Mark on it the angle of incidence and the angle of reflection.
Question 9. What is ozone? How does it protect the organisms on the Earth?
Question 10. (a) State the range of vision of a normal human eye.
(b) How do the ciliary muscles of a human eye help in the normal functioning of an eye?
Question 11. Why does the sun appear red during sunrise and sunset?
Question 12. A concave mirror produces three times magnified the real image of an object at 10 cm in front of it. Where is the image located?
Question 13. State the laws of refraction of light. If the speed of light in a vacuum is 3×108 ms−1. Find the speed of light in a medium of absolute refractive index 1.5.
Question 14. Mention the types of minor used as (i) rearview mirror, (ii) shaving mirrors. Give a suitable reason to justify your answer in each case.
Question 15. A spherical mirror produces an image of magnification −1 on a screen placed at a distance of 40 cm from the mirror:
(i) Write the type of mirror.
(ii) What is the nature of the image formed?
(iii) How far is the object located from the mirror?
(iv) Draw the ray diagram to show the image formation in this case.
Question 16. Why does the sun seem to rise two minutes before the actual sunrise and set two minutes after the actual sunset? Explain with the help of a labeled diagram.
Question 17. (a) What is meant by fossil fuel?
(b) Which fossil fuel is usually conserved when we save on electricity?
(c) At the present rate of consumption, how long will the known reserves of coal and petroleum last?
Question 18. Why does it take some time to see the objects in a dim room when you enter the room from bright sunshine outside?
Question 19. (a) Draw the ray diagrams to represent the nature, position and relative size of the image formed by a convex lens for the object placed:
(i) at 2F1 (ii) between F1 and 2F1 of a lens.
(b) The image of a candle flame placed at a distance of 30 cm from a spherical lens is formed on a screen placed on the other side of the lens at a distance of 30 cm from the lens. Identify the type of lens and write its focal length what will be the nature of the image formed if the candle flame is shifted 20 cm towards the lens. Draw a ray diagram to justify your answer.
Question 20. (a) With the help of ray diagrams, show the formation of an image by
(i) a hypermetropic eye and
(ii) correction of hypermetropia by using an appropriate lens.
(b) The near point of a person suffering from hypermetropia is at 50 cm from his eye. What is the power of the lens needed to correct this defect? (near point of the normal eye is 25cm)
(c) What might be the possible reasons for the Hypermetropia?
Question 21. A student has obtained an image of a distant object on a screen to determine the focal length F1 of the given lens. His teacher after checking the image gave him another lens of focal length F2 and asked to focus the same object on the same screen. The student found that to obtain a sharp image he has to move the lens away from the screen. From this finding, we may conclude that both the lenses given to the student weres:t
(a) Concave and F1 < F2
(b) Convex and F1 < F2
(c) Convex and F1 > F2
(d) Concave and F1 > F2
Question 22. Hypermetropia is a defect of vision with which a person can see the distant objects clearly but is unable to see the nearby objects distinctly. This defect might be caused due to which of the following reasons: (i) Eyeball being too short.
(ii) A short focal length of the eye lens.
(iii) The eyeball is too long.
(iv) The large focal length of the eye lens. Choose the correct option among the following:
(a)i and ii
(b) ii and iii
(c) i and iv
(d) iii and iv
Question 23. In an experiment to trace the path of a ray of light through a glass prism for different values of angle of incidence a student would find that the emergent ray in each case:
(a) Is parallel to the incident ray
(b) Is perpendicular to the incident ray
(c) Is parallel to the refracted ray
(d) Bends at an angle to the direction of the incident ray
Question 24. On the basis of their experiment, “To trace the path of a ray of light through a rectangular glass slab,” students of a class arrived at which one of the following conclusions:
(a) The angle of incidence is greater than the angle of emergence,
(b) The angle of emergence is smaller than the angle of refraction,
(c) Emergent ray is parallel to the refracted ray,
(d) Incident ray and emergent ray are parallel to each other.
Question 25. A student obtains a blurred image of an object on a screen by using a concave mirror. In order to obtain a sharp image on the screen, he will have to shift the mirror
(a) Towards the screen
(b) Away from the screen
(c) Either towards or away from the screen depending upon the position of the object.
(d) To a position very far away from the screen.
{IMPORTANT SCIENCE QUESTION}
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