Class 10th Physics Chapter 12


Total Marks: 20

1. Which of the following quantities is not changed during refraction of light?
Its direction Its frequency Its wavelength Its speed
2. A converging mirror with a radius of 20 cm creates a real image 30 cm from the mirror. What is the object distance?
+5.0 cm +7.5 cm +15 cm +20 cm
3. The index of refraction depends on
The focal length The speed of light The image distance The object distance
4. Which type of image is produce by the converging lens of human eye of it views a distant object?
Real, erect and same size Virtual, erect & diminished Real, inverted & diminished Virtual, inverted & magnified
5. If a ray of light in glass is incident on an air surface at an angle greater than the critical angle, the ray will :
Refract only Partially refract and partially reflect Diffract only Reflect only
6. The critical angle for a beam of light passing from water into air is 48.8 degrees. This means that all light rays with an angle of incidence greater than this angle will be
Absorbed Totally reflected Partially reflected and partially transmitted Totally transmitted
7. An ophthalmologist places a 2.00 D lens next to 0.35 D lens . The power of combination is.
2.35 D 2.00 D 1.65 D 0.35 D
8. Condition for total internal reflection are.
5 4 3 2
9. The center of the sphere , of which a concave or convex mirror is a part is known as.
Center of curvature Principal focus Optical center Radius of curvature
10. The radius of the spherical mirror is called.
Center of curvature Principal focus Optical center Radius of curvature
11. A fixed point length through which a ray of light does not change its path is called
Optical center Centre of curvature Focus Pole
12. Radius of curvature is of the focal length.
Three times Double Equal Half
13. If the radius of curvature of mirror is 30 cm , then its focal length will be
30 cm 20 cm 15 cm 10 cm
14. Concave mirrors are used as shaving mirror are.
Of small focal length Of half focal length Of suitable focal length Of large focal length
15. The Refractive index of water is
1.36 1.39 1.33 2.33
16. The change in the focal length of eye lens is called.
Modification Accomodation Induction Distinct Vision
17. For people in their early twenties with normal vision, the near point is located from eye about
20 cm 40 cm 25 cm 50 cm
18. The human eye has
Convex mirror Concave lens Convex lens Convex lens
19. To correct the defect of vision farsightedness which type of lens is used
Converging Diverging Both A & B None of these
20. At night we can see the stars in the sky without telescope.
300 3000 30000 300000