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ONLINE EXAM

Here are 50 questions on Light for Class 10th (JKBoSE) in the requested pattern:

Q1. Which three lie in the same plane according to the first law of refraction?
A. Incident ray, reflected ray, mirror
B. Incident ray, refracted ray, normal
C. Normal, mirror, image
D. Refracted ray, lens, axis
ANSWER: B

Q2. In which mirror is the image always virtual, erect, and diminished?
A. Plane mirror
B. Concave mirror
C. Convex mirror
D. Spherical mirror
ANSWER: C

Q3. The SI unit of power of a lens is:
A. Meter
B. Joule
C. Dioptre
D. Watt
ANSWER: C

Q4. Which phenomenon of light is responsible for the twinkling of stars?
A. Refraction
B. Reflection
C. Scattering
D. Dispersion
ANSWER: A

Q5. The splitting of white light into its constituent colours is called:
A. Reflection
B. Refraction
C. Dispersion
D. Scattering
ANSWER: C

Q6. A convex lens is also known as a:
A. Diverging lens
B. Converging lens
C. Plano lens
D. Cylindrical lens
ANSWER: B

Q7. The image formed by a plane mirror is:
A. Real and inverted
B. Real and erect
C. Virtual and erect
D. Virtual and inverted
ANSWER: C

Q8. For a real image formed by a concave mirror, the image distance is:
A. Positive
B. Negative
C. Zero
D. Infinite
ANSWER: A

Q9. The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant, according to:
A. Law of reflection
B. Snell’s law
C. Law of reversibility
D. Law of dispersion
ANSWER: B

Q10. The colour of light that deviates the least during dispersion through a prism is:
A. Violet
B. Red
C. Green
D. Blue
ANSWER: B

Q11. The part of the eye that controls the amount of light entering is:
A. Retina
B. Cornea
C. Pupil
D. Iris
ANSWER: D

Q12. A concave mirror always forms a virtual and erect image when the object is placed:
A. At infinity
B. At the focus
C. Between pole and focus
D. At the centre of curvature
ANSWER: C

Q13. The focal length of a plane mirror is:
A. Zero
B. Infinite
C. 10 cm
D. 1 m
ANSWER: B

Q14. The power of a lens with a focal length of -20 cm is:
A. +5 D
B. -5 D
C. +0.2 D
D. -0.2 D
ANSWER: B

Q15. Which defect of vision is corrected using a concave lens?
A. Hypermetropia
B. Myopia
C. Presbyopia
D. Astigmatism
ANSWER: B

Q16. The refractive index of a medium is defined with respect to:
A. Air
B. Vacuum
C. Water
D. Glass
ANSWER: B

Q17. In the human eye, the image is formed on:
A. Cornea
B. Lens
C. Retina
D. Iris
ANSWER: C

Q18. Which mirror is used as a shaving mirror?
A. Plane mirror
B. Convex mirror
C. Concave mirror
D. Spherical mirror
ANSWER: C

Q19. The angle of incidence is equal to the angle of reflection. This is the:
A. First law of refraction
B. Second law of refraction
C. First law of reflection
D. Second law of reflection
ANSWER: D

Q20. The speed of light is maximum in:
A. Glass
B. Water
C. Vacuum
D. Diamond
ANSWER: C

Q21. The mirror formula is given by:
A. 1/f = 1/v + 1/u
B. 1/f = 1/v – 1/u
C. 1/f = 1/u – 1/v
D. f = u + v
ANSWER: B

Q22. A lens forms a virtual, erect, and magnified image when the object is placed:
A. Between F and 2F of a convex lens
B. Beyond 2F of a convex lens
C. Between F and optical centre of a convex lens
D. At F of a convex lens
ANSWER: C

Q23. The phenomenon of light bending as it passes from one medium to another is called:
A. Reflection
B. Refraction
C. Dispersion
D. Scattering
ANSWER: B

Q24. Which colour of light has the maximum wavelength?
A. Violet
B. Blue
C. Red
D. Green
ANSWER: C

Q25. A real, inverted, and highly diminished image is formed by a concave mirror when the object is at:
A. Focus
B. Centre of curvature
C. Infinity
D. Between F and C
ANSWER: C

Q26. The lens used to correct hypermetropia is:
A. Concave lens
B. Convex lens
C. Plano-concave lens
D. Cylindrical lens
ANSWER: B

Q27. The magnification (m) for a mirror is given by:
A. m = v/u
B. m = -v/u
C. m = u/v
D. m = -u/v
ANSWER: B

Q28. The defect of vision due to the ageing of the eye lens is:
A. Myopia
B. Hypermetropia
C. Cataract
D. Presbyopia
ANSWER: D

Q29. Which mirror is used as a rear-view mirror in vehicles?
A. Plane mirror
B. Concave mirror
C. Convex mirror
D. Parabolic mirror
ANSWER: C

Q30. The refractive index of water is approximately:
A. 1.00
B. 1.33
C. 1.50
D. 2.42
ANSWER: B

Q31. The point where all rays parallel to the principal axis converge after reflection is called:
A. Centre of curvature
B. Pole
C. Focus
D. Aperture
ANSWER: C

Q32. A ray of light passing through the optical centre of a lens:
A. Emerges parallel to the principal axis
B. Emerges through the focus
C. Passes undeviated
D. Reflects back
ANSWER: C

Q33. The bending of light around obstacles is called:
A. Refraction
B. Reflection
C. Diffraction
D. Dispersion
ANSWER: C

Q34. The formula for the power (P) of a combination of lenses in contact is:
A. P = P1 + P2
B. P = P1 – P2
C. P = 1/(P1 + P2)
D. P = P1 * P2
ANSWER: A

Q35. In which medium does light travel the slowest?
A. Air
B. Water
C. Glass
D. Diamond
ANSWER: D

Q36. The angle of incidence for which the angle of refraction is 90° is called:
A. Critical angle
B. Refractive angle
C. Glancing angle
D. Emergent angle
ANSWER: A

Q37. The mirror used by dentists to see an enlarged image of teeth is:
A. Plane mirror
B. Convex mirror
C. Concave mirror
D. Spherical mirror
ANSWER: C

Q38. The lens formula is given by:
A. 1/f = 1/v – 1/u
B. 1/f = 1/v + 1/u
C. 1/f = 1/u – 1/v
D. f = v – u
ANSWER: A

Q39. The persistence of vision for the human eye is approximately:
A. 1/10th of a second
B. 1/16th of a second
C. 1/20th of a second
D. 1/25th of a second
ANSWER: B

Q40. The defect of the eye where the image is formed in front of the retina is:
A. Myopia
B. Hypermetropia
C. Presbyopia
D. Astigmatism
ANSWER: A

Q41. The power of a lens with a focal length of +50 cm is:
A. +0.5 D
B. +2 D
C. -2 D
D. +0.2 D
ANSWER: B

Q42. The phenomenon responsible for the blue colour of the sky is:
A. Refraction
B. Reflection
C. Scattering
D. Dispersion
ANSWER: C

Q43. For a virtual image formed by a concave mirror, the magnification is:
A. Positive and less than 1
B. Negative and less than 1
C. Positive and greater than 1
D. Negative and greater than 1
ANSWER: C

Q44. A convex lens always forms a virtual image when the object is placed:
A. Beyond 2F
B. Between F and 2F
C. At F
D. Between F and the optical centre (within focal length)
ANSWER: D

Q45. The least distance of distinct vision for a normal human eye is:
A. 25 cm
B. 25 m
C. Infinity
D. 2.5 cm
ANSWER: A

Q46. In a myopic eye, the image of a distant object is formed:
A. On the retina
B. Behind the retina
C. In front of the retina
D. On the iris
ANSWER: C

Q47. The lens present in the human eye is:
A. Concave lens
B. Convex lens
C. Plano-convex lens
D. Bifocal lens
ANSWER: B

Q48. The mirror with a reflecting surface curved outwards is:
A. Concave mirror
B. Convex mirror
C. Plane mirror
D. Parabolic mirror
ANSWER: B

Q49. The ratio of the speed of light in vacuum to the speed of light in a medium is called:
A. Critical angle
B. Refractive index
C. Focal length
D. Magnification
ANSWER: B

Q50. The formula for refractive index (n) in terms of speed of light is:
A. n = c/v
B. n = v/c
C. n = c * v
D. n = 1/(c*v)
ANSWER: A