# Ray Optics and Optical Instruments MCQ Questions Class 12 Physics Chapter 9

Ray Optics and Optical Instruments MCQ Questions Class 12 Physics Chapter 9

NCERT MCQ Questions for Class 12 Physics Chapter 9 Ray Optics and Optical Instruments. Ray Optics and Optical Instruments MCQ Questions with Answers from Class 12 Physics.

## Ray Optics and Optical Instruments MCQ Questions Class 12 Physics Chapter 9

Ray Optics and Optical Instruments Multiple Choice Questions with Answers Class 12 Physics Chapter 9 PDF is available.

1) The electromagnetic radiation belonging to the region of spectrum 400nm – 700nm is called as

a) Microwave

b) Infrared

c) Light

d) Gamma rays

Ans: c) light

2) The speed of light in vacuum is given as

a) 3*10-8 m/s

b) 3*108 km/s

c) 3*108 m/s

d) None

Ans: c) 3*108 m/s

3) The bundle of rays of light constitute to form the

a) Bundle of light

b) Packets of light

c) Both a and b

d) Beam of light

Ans: d) beam of light

4) The geometric centre of the spherical mirror is called as

a) Pole of the mirror

b) Optical centre

c) Centre of curvature

d) None

Ans: a) pole of the mirror

5) The geometric centre of spherical lens is called as

a) Pole of the mirror

b) Optical centre

c) Centre of curvature

d) None

Ans: b) optical centre

6) In spherical mirror, the line joining pole and the centre of curvature is called as

a) Optical axis

b) Principal axis

c) Major axis

d) None

Ans: b) principal axis

7) In case of spherical lenses, the line joining optical centre with its principal focus is called as

a) Optical axis

b) Principal axis

Ans: b) principal axis

8) The distances measured in the same direction as the incident light are taken as

a) Negative

b) Positive

c) Both a and b

d) None

Ans: b) positive

9) The distances measured in the direction opposite to the direction of incident light are taken as

a) Positive

b) Negative

c) Both a and b

d) None

Ans: b) negative

10) The heights measured upward with respect to X axis and normal to the principal axis of mirror or lens are taken as

a) Positive

b) Negative

c) Both a and b

d) None

Ans: a) positive

11) The heights measured downward with respect to X axis and normal to the principal axis of mirror or lens are taken as

a) Positive

b) Negative

c) Both a and b

d) None

Ans: b) negative

12) In case of concave mirror, the reflected rays converge at a point on the principal axis which is called as

a) Focus

b) Principal focus

c) Optical centre

d) Pole

Ans: b) principal focus

13) In case of convex mirror, the reflected rays appear to diverge from the point on the principal axis which is called as

a) Pole of the mirror

b) Optical centre

c) Principal focus

d) None

Ans: c) principal focus

14) The distance between the principal focus F and pole of the mirror P is called as

c) Focal length

d) None

Ans: c) focal length

15) If f is the focal length of the mirror then R = 2f, R is called as

c) Both a and b

d) None

16) If the rays originating from the point, actually meet at another point after reflection or refraction then that point is called as

a) Object of first point

b) Image of first point

c) Both a and b

d) None

Ans: b) image of first point

17) If the rays actually converge at a point after reflection or refraction then the image will be

a) Real image

b) Imaginary image

c) Both a and b

d) None

Ans: a) real image

18) If the rays do not actually meet but appear to diverge from the point when produced backwards then the image formed will be

a) Real image

b) Imaginary image

c) Both a and b

d) None

Ans: b) imaginary image

19) If the incident ray is parallel to the principal axis then after reflection

a) It doesn’t go through the focus of the mirror

b) It go through the focus of the mirror

c) It go through the pole of the mirror

d) None

Ans: b) it go through the focus of the mirror

20) If the ray of light is passing through the centre of curvature of a concave mirror or appearing to pass through centre of curvature in convex mirror then

a) Reflected ray pass through the focus

b) Reflected ray simply retraces it’s path

c) Reflected ray doesn’t pass through the focus

d) Reflected ray does not retraces it’s path

Ans: b) reflected ray simply retraces it’s path

21) If the ray of light passing through the focus of the concave mirror or appearing to pass through the focus of the convex mirror then

a) Reflected ray simply retraces it’s path

b) Reflected ray is parallel to principal axis

c) Both a and b

d) Reflected ray is not parallel to principal axis

Ans: b) reflected ray is parallel to principal axis

22) The ray of light incident at any angle at the pole then reflected ray

a) Doesn’t follows laws of reflection

c) Both a and b

d) None

Ans: b) follows laws of reflection

23) The mirror formula is given by

a) 1/f = 1/v – 1/u

b) 1/v = 1/f -1/u

c) 1/f = 1/v + 1/u

d) None

Ans: c) 1/f = 1/v + 1/u

24) The magnification in case of mirror is given by

a) M = object height/image height

b) M= image height/object height

c) M= -v/u

d) Both b and c

Ans: d) both b and c

25) The ray of light traveling from one transparent medium to another changes its direction of path in the second medium, this is called as

a) Reflection

b) Refraction

c) Dispersion

d) Polarisation

Ans: b) refraction

26) The incident ray, refracted ray and normal to the interface at the point of incidence all

a) Do not lie in the same plane

b) Lie in the same plane

c) Both a and b

d) None

Ans: b) lie in the same plane

27) The angle made by incident ray with the normal is called as

a) Angle of reflection

b) Angle of deviations

c) Angle of incidence

d) Angle of refraction

Ans: c) angle of incidence

28) The angle made by refracted  ray with the normal is called as

a) Angle of reflection

b) Angle of deviations

c) Angle of incidence

d) Angle of refraction

Ans: d) angle of refraction

29) The angle made by reflected ray with the normal is called as

a) Angle of reflection

b) Angle of incidence

c) Angle of deviations

d) Angle of refraction

Ans: a) angle of reflection

30) The angle made by incident ray with the interface separating two mafia is called as

a) Angle of deviations

b) Angle of incidence

c) Glancing angle

d) None

Ans: c) glancing angle

31) The ratio of sine of angle of incidence to the sine of angle of refraction remains constant for given pair of media and that constant is called as

a) Refractive index

b) Refractive index of first medium with respect to second medium

c) Refractive index of second medium with respect to first medium

d) None

Ans: c) refractive index of the second medium with respect to first medium

32) The ray of light traveling from rarer medium to denser medium

a) Bends away from the normal

b) Bends towards the normal

c) Does not changes its path

d) None

Ans: b) bends towards the normal

33) The ray of light traveling from denser medium to rarer medium

a) Bends away from the normal

b) Bends towards the normal

c) Does not changed its path

d) None

Ans: a) bends away from the normal

34) Denser medium has _____ optical density than the rarer medium.

a) Less

b) More

c) Zero

d) None

Ans: b) more

35) In case of refraction of light through parallel sided glass slab, the emergent ray is

a) Parallel to refracted ray

b) Not parallel to incident ray

c) Parallel to incident ray

d) None

Ans: c) parallel to incident ray

36) The bottom of the tank filled with water appear to be raised due to

a) Reflection

b) Dispersion

c) Refraction

d) Polarisation

Ans: c) refraction

37) The sun is visible a little before actual sunrise and untill a little after the actual sunset due to

a) Atmospheric reflection

b) Atmospheric scattering

c) Atmospheric refraction

d) Both b and c

Ans: c) atmospheric refraction

38) When a ray of light traveling from denser medium to rarer medium it get partly reflected back into the same medium and partly refracted to the second medium, this is called as

a) External reflection

b) Internal reflection

c) Both a and b

d) Total internal reflection

Ans: b) internal reflection

39) The angle of incidence corresponding to an angle of refraction 90° is called as

a) Emerging angle

b) Deviation angle

c) Particular angle

d) Critical angle

Ans: d) critical angle

40) The refractive index of the diamond is

a) 1.52

b) 1.62

c) 2.42

d) None

Ans: c) 2.42

41) Which of the following shows total internal reflection

a) Mirage

b) Prism

c) Diamond

d) All

Ans: d) all

42) The light traveling through optical fibres is due to

a) Internal reflection

b) Total internal reflection

c) Refraction

d) Scattering

Ans: b) total internal reflection

43) The lens formula is given by

a) 1/f = 1/v + 1/u

b) 1/f = 1/v – 1/u

c) 1/v = 1/f – 1/u

d) None

Ans: b) 1/f = 1/v – 1/u

44) The focus on the side of the original source of light is called as____ whereas the focus on the other side is called as___

a) Second focal point, first focal point

b) First focal point, second focal point

c) Both a and b

d) None

Ans: b) first focal point, second focal point

45) The ray of light passing through the optical centre of the lens after refraction

a) Emerges with deviation

b) Emerges without deviations

c) Both a and b

d) None

Ans: b) emerges without deviation

46) Magnification in case of lenses is given by

a) M = image height/ object height

b) M= -v/u

c) M= v/u

d) Both a and c

Ans: d) both a and c

47) The measure of convergence or divergence of a lens which a lens introduces in the light falling on it is called as

a) Power of lens

b) Optical density of lens

c) Magnification of lens

d) None

Ans: a) power of lens

48) A lens of shorter focal length bends

a) Incident light less

b) Reflected light more

c) Incident light more

d) None

Ans: c) incident light more

49) The SI unit of power of lens is

a) Watt

b) Joule

c) Dioptre

d) None

Ans: c) dioptre

50) 1D =

a) 1m

b) 1cm

c) 1m-1

d) 1cm-1

Ans: c) 1m-1

51) The power of lens is given as

a) P= 1/f

b) F= 1/P

c) Both a and b

d) P= 2f

Ans: c) both a and b

52) If the power of the lens is +2.5D then it’s focal length will be

a) -40cm

b) 40cm

c) -40m

d) 40m

Ans: b) 40cm

53) If the power of the lens is -4.0 D then it’s focal length is

a) 25cm

b) -25cm

c) 25m

d) -25m

Ans: b) -25cm

54) If the any number of thin lenses in contact of focal length f1, f2, .. then effective focal length of their combination is given by

a) 1/f = 1/f1 + 1/f2 + …

b) f = f1 + f2 + …

c) f = f1 – f2 -…

d) 1/f = 1/f1 – 1/f2 -…

Ans: a) 1/f = 1/f1 + 1/f2 + …

55) If the any number of thin lenses are in contact having power as P1, P2,… then effective power of their combination is given by

a) 1/P = 1/P1 + 1/P2 +…

b) P= P1 + P2 + …

c) P = P1 – P2 – P3-…

d) 1/P = 1/P1 – 1/P2 -..

Ans: b) P= P1 + P2 + …

56) If the may number of thin lenses are in contact having magnification m1, m2,… then effective magnification of their combination is given by

a) M= m1*m2*..

b) M= 1/m1*1/m2*…

c) M= m1 – m2 – …

d) M= m1 + m2 +…

Ans: a) M = m1*m2*m3*…

57) The system of combination of lenses is commonly used in designing lenses for

a) Microscopes

b) Telescope

c) Cameras

d) All

Ans: d) all

58) In case of prism, the angle between emergent ray and the direction of incident ray is called as

a) Glancing angle

b) Refracting angle

c) Angle of deviation

d) None

Ans: c) angle of deviation

59) The angle of deviation depends on the

a) Angle of refraction

b) Angle of incidence

c) Both a and b

d) None

Ans: b) angle of incidence

60) The dispersion takes place because

a) Refractive index of medium is same for different frequencies

b) Refractive index of medium is different for different frequencies

c) Both a and b

d) None

Ans: b) refractive index of medium is different for different frequencies

61) Thick lenses shows chromatic aberration due to

a) Refraction of light

b) Scattering of light

c) Dispersion of light

d) Total internal reflection of light

Ans: c) dispersion of light

62) The rainbow is the example of _____ of sunlight by the water drops in the atmosphere.

a) Refraction

b) Scattering

c) Reflection

d) Dispersion

Ans: d) dispersion

63) Light of shorter wavelength is scattered ____ than the light of longer wavelength.

a) Less

b) Much more

c) Both a and b

d) None

Ans: b) much more

64) The amount of scattering is inversely proportional to

a) Cube of wavelength

b) Square of wavelength

c) Fourth power of wavelength

d) None

Ans: c) fourth power of wavelength

65) The amount of scattering is inversely proportional to fourth power of wavelength is called as

a) Rayleigh’s dispersion

b) Rayleigh’s scattering

c) Rayleigh’s reflection

d) None

Ans: b) Rayleigh’s scattering

66) A simple magnifier or microscope is a

a) Diverging lens of small focal length

b) Converging lens of small focal length

c) Diverging lens of large focal length

d) Converging lens of large focal length

Ans: b) converging lens of small focal length

67) The magnification formula for microscope is given by

a) M = ( 1 + f/D)

b) M = ( 1 – D/f)

c) M = (1 + D/f)

d) None

Ans: c) M = (1 + D/f)

68) For much larger magnification, one uses two lenses, one compounding the effect of the other and it is known as

a) Microscope

b) Compound microscope

c) Both a and b

d) Telescope

Ans: b) compound microscope

69) In compound microscope, the lens nearest to object is called as

a) Objective

b) Eyepiece

c) Both a and b

d) None

Ans: a) objective

70) The _____ is used to provide angular magnification of distant objects.

a) Microscope

b) Compound microscope

c) Telescope

d) None

Ans: c) telescope

Updated: April 12, 2023 — 10:39 am