Xth Science CBSE Question Bank - Class 10 CBSE Hot Questions
NCERT Science Sample Questions
Class 10 Physics (Light: Reflection and Refraction)
frequently asked questions
01. What are the various uses of concave mirrors?
02. What are the various sign conventions for reflection by spherical mirrors?
03. A convex mirror used for rear view on an automobile has a radius of curvature of 3m. If a bus is located at 5m from this mirror, find the position, nature and size of the image.
04. What are the various factors of refraction of light?
05. (a) Define Power of a Lens. Write its SI unit.
(b) Find the focal length of a lens of power 2 D. What type of lens is this?
one mark questions
01. For what position of an object a real and diminished image is formed by a concave mirror?
02. What is the relation between the focal length and radius of curvature of a spherical mirror?
03. Where should an object be placed in front of the concave mirror so as to obtain its magnified erect image?
04. Explain why concave mirrors are used as shaving mirrors.
05. What type of mirrors is used in making periscopes?
06. What is the difference between a real image and a virtual image?
07. What is the nature of light?
08. If the radius of curvature of a spherical mirror is 20 cm, what is its focal length?
09. Define the principal focus of a concave mirror.
10. If an object is placed at the focus of a concave mirror, where is the image formed?
11. What is refraction of light?
12. The focal length of convex lens is 25 cm. What is its power?
13. What is the value of refractive index of glass with respect to air?
14. Where should an object be placed in front of a convex lens, so as to obtain its real, magnified and inverted image?
15. Which of the two is a diverging lens: convex or concave?
16. Which type of lens has a positive power?
17. Write the relation between the angle of incidence and angle of refraction for a medium.
18. What type of image is formed: (a) in a plane mirror (b) on a cinema screen.
19. For what position of an object, a concave mirror forms an enlarged virtual image?
20. Name the phenomenon due to which a pool of water appears less deep than it really is.
21. Name the type of mirror used by a dentist.
22. What is the speed of light in glass?
23. Which mirror is used as Doctor’s head mirror?
24. Name the type of mirror which is used in the head lights of a car. Why is it used for this purpose?
25. What is lateral inversion?
26. Define the principal focus of a convex lens.
27. Which mirror has a wider view of field, concave or convex mirror?
28. Name the spherical mirror which has (a) virtual principal focus (b) real principal focus.
29. Define linear magnification produced by a mirror.
30. What is the mirror’s formula?
31. The power of a combination of two lenses X and Y is 5D. If the focal length of lens X be 15 cm, what is the focal length of lens Y?
32. A ray of light is incident normally on a plane mirror. What will be the angle of incidence and angle of reflection?
33. The power of a lens is +4D. What kind of lens is it and what is its focal length?
34. What is the unit of refractive index?
35. Name the physical quantity whose unit is dioptre.
two marks questions
01. What are the various effects of refraction of Light?
02. Define Snell’s law of Refraction.
03. What is the cause of refraction of light?
04. Mention various uses of plane mirror.
05. Draw a labeled diagram to show the - (a) optical center (b) principal axis (c) principal focus (d) focal length of a convex lens.
06. The refractive index of water is 4/3 and for glass it is 3/2, with respect to air. What is the Refractive Index of glass with respect to water?
07. Write a tabular formula (summary) of images formed by a concave mirror.
08. What are the various signs of convention for spherical mirrors?
09. Describe with help of a ray diagram the nature, size and position of the image formed when an object is placed in front of a convex lens between focus and optical center.
10. What are the various laws of refraction of light?
11. Write the characteristics of an image formed by a plane mirror.
12. What are the uses of concave mirrors?
13. What are the various signs of convention for spherical lenses?
14. What are the various rules of obtaining images formed by concave lens?
15. Write a tabular formula (summary) of images formed by a convex mirror.
16. Define optically Rarer Medium and optically Denser Medium.
17. Explain with the help of a diagram why the convex lens is called converging lens.
three marks questions
01. At what distance from a concave mirror of focal length 10 cm should an object be placed, so that its real image is formed 20 cm from the mirror?
02. A 2 cm tall object is placed perpendicular to the principal axis of a convex lens of focal length 10 cm. The distance of the object from the lens is 15 cm. Find the nature, position, size of the image. Also find its magnification.
03. An object of size 7 cm is placed at 27 cm in front of a concave mirror of focal length 18 cm. At what distance from the mirror should a screen be placed so that a sharp focused image can be obtained?
04. A concave mirror produces 3 times enlarged real image of an object placed at 10 cm in front of it. Where is the image located?
05. Describe the nature of the image formed when the object is placed at a distance of 20 cm from a concave mirror of focal length 10 cm.
06. Light, of wavelength of 500nm in air, enters a glass plate of refractive index 1.5 Find speed, frequency and wavelength of light in glass. Assume that the frequency of light remains the same in both media.
07. A convex mirror used in automobile has 3m radius of curvature. If a bus is located at 5m from this mirror, find the position, nature and size of the image.
08. An object 5cm high is held 25cm away from a converging lens of focal length 10cm. Find the position, nature and size of the image formed. Also draw the ray diagram.
09. An object 5cm high is held 10cm away from a convex mirror of radius of curvature 30cm. Find the position, nature and size of the image formed.
10. An object is placed at a distance of 12cm in front of a concave mirror. It forms a real image 4 times larger than the object. Calculate the distance of the image from the mirror.
11. An object placed 20cm in front of a mirror is found to have an image 15cm (i) in front of it (ii) behind the mirror. Find the focal length of the mirror and the kind of mirror in each case.
12. Find the position and nature of image of an object 5cm high and 10cm in front of a convex lens of focal length 6cm.
13. An object is placed at a distance of 100cm from a converging lens of focal length 40cm.
(i) What is the nature of the image?
(ii) What is the position of the image?