61)Read the following two statements and pick the correct answer:
A) Only (a) is true
B) Only (b) is true
C) Both (a) and (b) are true
D) Both (a) and (b) are false
View Answer
A) Only (a) is true
62)Focal length of a lens depends on
A) material of the lens
B) radius of curvature
C) Both material of the lens and radius of curvature
D) None
View Answer
C) Both material of the lens and radius of curvature
63)The angle of refraction of a light ray is the angle between
A) incident ray and refracted ray
B) refracted ray and interface separating the two media
C) normal ray and incident ray
D) normal ray and refracted ray
View Answer
D) normal ray and refracted ray
64)The extent of the change in the direction that takes place when a light ray travels from one medium to another is given by
A) critical angle
B) focal length
C) refractive index
D) focal power
View Answer
C) refractive index
65)The refractive index of a material is 1. If the speed of light in vacuum is 3×108 m/s, then the speed of light in that material is
A) 0.3 x108m/s
B) 3×108m/s
C) 4 x108m/s
D) 108m/s
View Answer
B) 3×108m/s
Explanation:Speed of light in material
= Speed of light in vaccum/Index of a material
= 3 x 108/1 m/s
= 3 x 108 m/s
66)In which of the following cases of convex lens, a virtual image is formed?
A) When the object is placed at the centre of curvature
B) When the’ object is placed beyond the centre of curvature
C) When the object is placed between the centre of curvature and focal point
D) When the object is placed between the focal point and optic centre
View Answer
D) When the object is placed between the focal point and optic centre
67)A curved surface of radius of curvature R is separating the two media of refractive indices n1 and n2. If u and v are object and image distances respectively, then their relation is
A)
B)
C)
D)
View Answer
A)
68)An image is formed at a distance of 30 cm from the centre of convex lens of focal length 15 cm. The object distance is
A) 2 cm
B) 15 cm
C) 30 cm
D) 45 cm
View Answer
C) 30 cm
Explanation:Focal length of a convex lens = f = 15 cm
Object distance = u = – u = ?
Image distance = v = 30 cm
1/f = 1/v – 1/(-u) ⇒ 1/f = 1/v + 1/u
∴ 1/u =1/f- 1/v = 1/15 – 1/30 = 2-1/30 = 1/30
∴ u = 30 cm
69)Which part of the human eye contains ‘rods’ and ‘cones’ to receive the light signals?
A) Cornea
B) Iris
C) Pupil
D) Retina
View Answer
D) Retina
70)For a person with myopia defect, the image of the distant object is formed
MCQBits provides free online MCQ practice tests for competitive exams, school exams, and entrance tests in India. Practice chapter-wise multiple choice questions, previous year papers, and mock tests with answers to improve your exam performance.
Prepare for TSPSC, APPSC, TS Polycet, CBSE Class 10, SSC,UPSC, RRB and other government exams with regularly updated quizzes and important questions. About Us | Contact Us | Privacy Polocy
