Q.1. SI unit of power of a lens i
(A) joule
(B) diopter
(C) candela
(D) watt
Ans :- (B)
Q.2. The radius of curvature of plane mirror is
(A) infinite
(B) zero
(C) + 5cm
(D) – 5 cm
Ans :- (A)
Q.3. A bi-convex lens can form a virtual image if the object is placed
(A) between the lens and its focus
(B) at the focus
(C) between ƒand 2ƒ
(D) at infinity
Ans :- (A)
Q.4. The final image in astronomical telescope is
(A) real and erect
(B) real and inverted
(C) virtual and inverted
(D) virtual and erect
Ans :- (C)
Q.5. The critical angle of light passing from glass to air is minimum for
(A) Red colour
(B) Green colour
(C) Yellow colour
(D) Violet colour
Ans :- (D)
Q.6. Which of the following phenomena taken place when a monochromatic light in incident of a prism ?
(A) Dispersion
(B) Deviation
(C) Interference
(D) All of the above
Ans :- (A)
Q.7. When a ray of light enters a glass slab it’s wavelength
(A) decreases
(B) increases
(C) remains unchanged
(D) data are not complete
Ans :- (A)
Q.8. A bi-convex lens (μ-1.5) has equal curvature each of 20 cm. The power of the lens is
(A) 5D
(B) 10D
(C) 2.5 D
(D) 20 D
Ans :- (A)
Q.9. Cause of mirage is
(A) refraction and total internal reflection
(B) diffraction
(C) scattering
(D) interference
Ans :- (A)
Q.10. The focal length of a lens μ = 1.5 in air is 20 cm. Its focal length in medium of refractive index 1.5 is
(A) 20 cm.
(B) 40 cm.
(C) 10 cm.
(D) ∞
Ans :- (D)
Q.11. The image formed by objective lens of a compound microscope is
(A) Virtual and diminished
(B) Real and diminished
(C) Real and large
(D) Virtual and large
Ans :- (C)
Q.12. A convex lens is dipped in a liquid, whose refractive index is equal to refractive index of material of lens. Then its focal length will
(A) become zero
(B) become infinite
(C) decrease
(D) increase
Ans :- (B)
Q.13. When the tube length of microscope is increased, its magnifying power?
(A) increases
(B) decreases
(C) becomes zero
(D) remains unchanged
Ans :- (A)
Q.14. To remove hyper metropia lens used is
(A) Convex
(B) Concave
(C) Cylindrical
(D) Plano-convex
Ans :- (A)
Q.15. The upper half of a convex Lens is blackned, size of image formed by it
(A) Increases
(B) Decreases
(C) Becomes of less intensity
(D) None of these
Ans :- (C)
Q.16. When concave lens of glass is immersed in water it works as
(A) Less convergent
(B) More convergent
(C) Less divergent
(D) More divergent
Ans :- (C)
Q.17. The minimum distance between an object and real image formed by conversing lens of focal length ƒ will be
(A) greater than 4ƒ
(B) less than 4ƒ
(C) equal to 2ƒ
(D) equal to 4ƒ
Ans :- (D)
Q.18. The angle of minimum Deviation for thin prism of refractive index (μ) is
(A) (1- μ)A
(B) (μ -1)A
(C) (μ +1)A
(D) (μ +1)A²
Ans :- (B)
Q.19. Critical angle for light moving from medium I to medium II is θ. The speed of light in medium I is ν. Then speed in medium II is
(A) ν(1-cosθ)
(B) ν/sinθ
(C) ν/cosθ
(D) ν(1-sinθ)
Ans :- (B)
Q.20. A magnifying glass is to be used at the fixed object distance of 1 inch. If it is to produce an erect image 5 items magnified, its focal length should be
(A) 0.2″
(B) 0.8″
(C) 1.25″
(D) 5″
Ans :- (C)
Q.21. The resolving power of human eye (in minute) is
(A) 1/60
(B) 1
(C) 10
(D) 1/2
Ans :- (B)
Q.22. Which has larger difference in focal length ?
(A) in telescope
(B) compound microscope
(C) in both
(D) None
Ans :- (A)
Q.23. The part of eye to see the size and colour of objects is
(A) iris
(B) eye lens
(C) optic nerves
(D) None of these
Ans :- (C)
Q.24. A virtual image larger than object is formed in a
(A) Convex mirror
(B) Concave mirror
(C) plane mirror
(D) Concave lens
Ans :- (B)
Q.25. The focal length of a lens does not depend upon
(A) refractive index of lens
(B) distance of object
(C) the two radii of curvature of the lens
(D) None of these
Ans :- (B)
Q.26. Given a point source of light, which of the following can produce a parallel beam of light?
(A) convex mirror
(B) concave mirror
(C) both ‘A’ and ‘B’
(D) none of these
Ans :- (B)
Q.27. A magnified virtual image can be formed by
(A) convex mirror
(B) concave mirror
(C) plane mirror
(D) concave lens
Ans :- (B)
Q.28. A diminished virtual image can be formed by
(A) plane mirror
(B) concave mirror
(C) convex mirror
(D) none of these
Ans :- (C)
Q.29. The vertically possible number of images of an object placed between two parallel mirrors is
(A) one
(B) two
(C) four
(D) infinite
Ans :- (D)
Q.30. The field of view is maximum for
(A) plane mirror
(B) concave mirror
(C) convex mirror
(D) none of these
Ans :- (C)
Q.31. A person sees the face in the mirror and finds big image, the mirror will be
(A) plane mirror
(B) concave mirror
(C) convex mirror
(D) none of these
Ans :- (B)
Q.32. focal length of plane mirror is
(A) zero
(B) infinity
(C) both ‘A’and’B’
(D) none of these
Ans :- (B)
Q.33. The power of the plane mirror is
(A) zero
(B) infinity
(C) unity
(D) none of these
Ans :- (A)
Q.34. The magnification of the plane mirror is
(A) zero
(B) infinity
(C) unity
(D) none of these
Ans :- (C)
Q.35. Refractive index is highest for
(A) water
(B) glass
(C) quartz
(D) diamond
Ans :- (D)
Q.36. The velocity of light is maximum is
(A) air
(B) glass
(C) water
(D) vacuum
Ans :- (D)
Q.37. Smell’s law does not hold for
(A) oblique incidence
(B) grazing incidence
(C) normal incidence
(D) none of these
Ans :- (C)
Q.38. When a ray of light passes through the optical centre of a lens it is
(A) deviated
(B) displaced
(C) deiviated and displaced
(D) none of these
Ans :- (B)
Q.39. The deviation of a ray of light produced by a prism depends on
(A) angle of prism only
(B) angle of incidence
(C) refractive index only
(D) all of above
Ans :- (D)
Q.40. If there were no atmosphere, then the length of day on the earth will be
(A) decrease
(B) remains the same
(C) increase
(D) none of these
Ans :- (A)
Q.41. A bubble of air inside water appears shining due to
(A) refraction
(B) reflection
(C) diffraction
(D) total internal reflection
Ans :- (D)
Q.42. The optical centre of a lens
(A) always lies with in the material of the lens
(B) always lies out side the material of the lens
(C) may lie inside, outside or on the surface of the lens
(D) always lies on the surface of the lens
Ans :- (C)
Q.43. A bio convex lens conform a virtual image if the object is placed
(A) at infinity
(B) at the focus
(C) between the lens and its focus
(D) none of these
Ans :- (C)
Q.44. A converging lens is that wich
(A) collects rays
(B) spreads rays
(C) form real image only
(D) forms virtual image only
Ans :- (A)
Q.45. A well cut diamond sparkles due to its
(A) hardness
(B) high density
(C) large refractive index
(D) none of these
Ans :- (C)
Q.46. Myopia is corrected by the use of
(A) concave lens
(B) convex lens
(C) cylindrical lens
(D) none of these
Ans :- (A)
Q.47. The normal eye is most relaxed when it is focussed on an object at
(A) 25 mm away
(B) 25 cm away
(C) 25 m away
(D) infinity
Ans :- (D)
Q.48. Which of the following colour suffering by minimum deviation through the prism
(A) red
(B) violet
(C) green
(D) none of these
Ans :- (A)
Q.49. Sky appears blue due to
(A) refraction of light
(B) reflection of light
(C) dispersion of light
(D) scattering of light
Ans :- (D)