exam9

ONLINE EXAM

Q1. Which three lie in the same plane according to 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. The constant ratio in refraction law is between A. Angle of incidence and normal B. Sine of angle of incidence and sine of refraction C. Speed and wavelength D. Angle of refraction and glass thickness ANSWER: B Q3. The law relating sine of angles is called A. Newton’s law B. Fresnel law C. Snell’s law D. Einstein’s law ANSWER: C Q4. Refractive index is defined as A. Bending of light B. Ratio of speeds of light C. Reflection angle D. Color shift of light ANSWER: B Q5. Symbol used for refractive index of medium 2 relative to medium 1 is A. n12 B. n21 C. nm D. R ANSWER: B Q6. Refractive index represents change in A. Wavelength B. Direction of light C. Speed of light D. Brightness ANSWER: C Q7. Light travels fastest in A. Water B. Glass C. Vacuum D. Oil ANSWER: C Q8. Speed of light in vacuum is A. 3×10⁶ m/s B. 3×10⁷ m/s C. 3×10⁸ m/s D. 3×10⁹ m/s ANSWER: C Q9. Speed of light in air compared to vacuum is A. Much more B. Same C. Marginally less D. Zero ANSWER: C Q10. Speed of light in water is A. Same as vacuum B. Slightly more C. Considerably less D. Infinite ANSWER: C Q11. If light goes from medium 1 to medium 2, refractive index is A. v₂/v₁ B. v₁/v₂ C. v₁ + v₂ D. v₂ − v₁ ANSWER: B Q12. Refractive index depends on A. Shape B. Color C. Speed in medium D. Size ANSWER: C Q13. Angle of incidence is represented by A. r B. i C. n D. v ANSWER: B Q14. Angle of refraction is denoted by A. r B. i C. n D. c ANSWER: A Q15. Refractive index of water is A. 1.00 B. 1.25 C. 1.33 D. 1.50 ANSWER: C Q16. Refractive index indicates A. Mass density B. Optical density C. Thickness D. Brightness ANSWER: B Q17. When light enters another medium obliquely, it A. Stops B. Bends C. Reflects D. Vanishes ANSWER: B Q18. Refractive index of medium 1 with respect to medium 2 is A. n21 B. n12 C. nm D. R ANSWER: B Q19. Absolute refractive index is taken with respect to A. Water B. Glass C. Air or vacuum D. Oil ANSWER: C Q20. Symbol for absolute refractive index is A. n21 B. nm C. n12 D. r ANSWER: B Q21. Formula for absolute refractive index is A. v/c B. c/v C. v₁/v₂ D. v₂/v₁ ANSWER: B Q22. Refraction occurs due to change in A. Direction only B. Wavelength only C. Speed only D. Speed and direction ANSWER: D Q23. Refractive index is a A. Vector B. Scalar C. Force D. Energy ANSWER: B Q24. Snell’s law is valid for A. Given color and given media B. All colors equally C. Vacuum only D. Water only ANSWER: A Q25. Refractive index changes when A. Medium changes B. Object moves C. Angle changes D. Thickness changes ANSWER: A Q26. Normal is drawn A. Parallel to surface B. Perpendicular to surface C. Slanted D. Curved ANSWER: B Q27. No refraction occurs when incidence is A. Oblique B. Large C. Normal D. Small ANSWER: C Q28. sin i / sin r is A. Random B. Constant C. Zero D. Infinite ANSWER: B Q29. Refraction proves that light changes A. Color B. Speed C. Shape D. Size ANSWER: B Q30. Higher refractive index indicates A. Higher speed B. Lower speed C. Same speed D. Random speed ANSWER: B Q31. When light slows down, refractive index A. Falls B. Rises C. Vanishes D. Reverses ANSWER: B Q32. Refraction happens at A. Center of medium B. Mirror C. Boundary of two media D. Source ANSWER: C Q33. Refractive index of vacuum is A. 0 B. 1 C. 1.33 D. Infinity ANSWER: B Q34. Glass has higher refractive index than A. Air B. Diamond C. Water D. Plastic ANSWER: A Q35. Snell’s law relates A. Angles B. Sines of angles C. Speeds D. Distances ANSWER: B Q36. Refraction occurs in A. Mirrors B. Transparent media C. Metals D. Vacuum only ANSWER: B Q37. Maximum slowing of light occurs in A. Air B. Water C. Glass D. Vacuum ANSWER: C Q38. Symbol for refractive index is A. f B. m C. n D. R ANSWER: C Q39. Refractive index increases when speed A. Increases B. Decreases C. Remains same D. Is random ANSWER: B Q40. Refractive index depends on color because of A. Reflection B. Dispersion C. Absorption D. Expansion ANSWER: B Q41. Law of refraction states ratio is constant for A. All light B. White light only C. Given color D. Night light ANSWER: C Q42. Refractive index compares speed in A. Two media B. Two mirrors C. Same medium D. Vacuum only ANSWER: A Q43. If medium 2 is optically denser, refracted ray bends A. Towards the normal B. Away from the normal C. Straight D. Backwards ANSWER: A Q44. Absolute refractive index compares medium with A. Water B. Glass C. Air or vacuum D. Oil ANSWER: C Q45. Unit of refractive index is A. m/s B. Meter C. No unit D. Second ANSWER: C Q46. Smaller wavelength means A. Lower refractive index B. Higher refractive index C. No effect D. Infinite index ANSWER: B Q47. Light entering a denser medium becomes A. Faster B. Slower C. Same D. Zero ANSWER: B Q48. Refraction shows light does not travel A. In vacuum B. In air only C. At same speed in all media D. In lanes ANSWER: C Q49. Medium with lowest refractive index is A. Glass B. Water C. Air D. Diamond ANSWER: C Q50. Highest refractive index among the following is A. Air B. Water C. Glass D. Diamond ANSWER: D SUBMIT EXAM