NEET Physics Ray Optics and Optical Instruments MCQs Set A

a) 7.5°

b) 5°

c) 15°

d) 2.5°

Answer: 7.5°

Question: A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first colour to emerge is

a) red

b) violet

c) green

d) blue

Answer: red

Question: An object approaches a convergent lens from the left of the lens with a uniform speed 5 m/s and stops at the focus. The image

a) moves away from the lens with a non-uniform acceleration

b) moves towards the lens with a non-uniform acceleration

c) moves away from the lens with an uniform acceleration

d) moves away from the lens with an uniform speed 5 m/s

Answer: moves away from the lens with a non-uniform acceleration

Question: A passenger in an aeroplane shall

a) may see a primary and a secondary rainbow as concentric circles

b) may see a primary and a secondary rainbow as concentric arcs

c) shall never see a secondary rainbow

d) never see a rainbow

Answer: may see a primary and a secondary rainbow as concentric circles

Question:  You are given four sources of light each one providing a light of a single colour - red, blue, green and yellow. Suppose the angle of refraction for a beam of yellow light corresponding to a particular angle of incidence at the interface of two media is 90°. Which of the following statements is correct if the source of yellow light is replaced with that of other lights without changing the angle of incidence?

a) The beam of blue light would undergo total internal reflection

b) The beam of red light would bend towards normal while it gets refracted through the second medium

c) The beam of red light would undergo total internal reflection

d) None of these

Answer: The beam of blue light would undergo total internal reflection

Question: The radius of curvature of the curved surface of a planoconvex lens is 20 cm. If the refractive index of the material of the lens be 1.5, it will

a) act as a convex lens irrespective of the side on which the object lies

b) act as a concave lens irrespective of side on which the object lies

c) act as a concave lens for the objects that lie on its curved side

d) act as a convex lens only for the objects that lie on its curved side

Answer: act as a convex lens irrespective of the side on which the object lies

Question: The phenomena involved in the reflection of radiowaves by ionosphere is similar to

a) total internal reflection of light in air during a mirage

b) dispersion of light by water molecules during the formation of a rainbow

c) scattering of light by the particles of air

d) reflection of light by a plane mirror

Answer:  total internal reflection of light in air during a mirage

Question:  The direction of ray of light incident on a concave mirror is shown by PQ while directions in which the ray would travel after reflection is shown by four rays marked 1, 2, 3 and 4 (figure). Which of the four rays correctly shows the direction of reflected ray?

a) 2

b) 3

c) 4

d) 5

Answer: 2

Question:  The optical density of turpentine is higher than tnat of water while its mass density is lower. Figure shows a layer of turpentine floating over water in a container. For which one of the four rays incident on turpentine in figure, the path shown is correct?

a) 2

b) 3

c) 4

d) 1

Answer: 2

More Questions.....................................

Question: An equilateral prism is placed on a horizontal surface. A ray PQ is incident onto it. For minimum deviation

a) QR is horizontal

b) RS is horizontal

c) Any one will be horizontal

d) PQ is horizontal

Answer: QR is horizontal

Question:  A light ray is incident perpendicularly to one face of a 90° prism and is totally internally reflected at the glass-air interface. If the angle of reflection is 45°, we conclude that the refractive index

a)

b)

c)

d)

Answer:

Question:

a) Assertion is correct, reason is correct; reason is not a correct explanation for assertion

b) Assertion is correct, reason is incorrect

c) Assertion is incorrect, reason is correct

d) Assertion is correct, reason is correct; reason is a correct explanation for assertion.

Answer: Assertion is correct, reason is correct; reason is not a correct explanation for assertion

Question: A man 160 cm high stands in front of a plane mirror. His eyes are at a height of 150 cm from the floor. Then the minimum length of the plane mirror for him to see his full length image is

a) 80 cm

b) 340 cm

c) 170 cm

d) 85 cm

Answer: 80 cm

Question:   The angle of incidence for a ray of light at a refracting surface of a prism is 45° . The angle of prism is 60°. If the ray suffers minimum deviation through the prism, the angle of minimum deviation and refractive index of the material of the prism respectively, are

a)

b)

c)

d) None of these

Answer:

Question:  A astronomical telescope has objective and eyepiece of focal lengths 40 cm and 4 cm respectively. To view an object 200 cm away from the objective, the lenses must be separated by a distance :

a) 54.0 cm

b) 50.0 cm

c) 46.0 cm

d) 37.3 cm

Answer:  54.0 cm