CLASS 10 {Boardwallah}

MCQS OF LIGHT CHAPTER 1.The SI unit of power of a lens is: A) Metre B) Dioptre C) Watt D) Joule 2.Which mirror is used as a shaving mirror? A) Plane mirror B) Convex mirror C) Concave mirror D) None of these 3.The image formed by a plane mirror is: A) Real and inverted B) Virtual and erect C) Real and erect D) Virtual and inverted 4.A convex lens is also known as: A) Diverging lens B) Converging lens C) Cylindrical lens D) Plane lens 5.The bending of light when it passes from one medium to another is called: A) Reflection B) Refraction C) Dispersion D) Scattering 6.The focal length of a plane mirror is: A) Zero B) Infinity C) One metre D) Negative 7.The mirror formula is: 8.Which mirror is used as a rear-view mirror in vehicles? A) Plane mirror B) Concave mirror C) Convex mirror D) None of these 9.The image formed by a convex mirror is always: A) Real and inverted B) Virtual, erect and diminished C) Real and magnified D) Virtual and magnified 10.The refractive index of air is approximately: A) 1 B) 1.33 C) 1.5 D) 2 11.The power of a lens is measured in: A) Watt B) Metre C) Dioptre D) Newton 12.A concave lens always forms an image that is: A) Real and inverted B) Virtual, erect and diminished C) Real and magnified D) Virtual and magnified 13.According to the law of reflection: A) Angle of incidence = Angle of reflection B) Angle of incidence > Angle of reflection C) Angle of reflection = 90° D) None of these 14.Which lens is thicker at the centre than at the edges? A) Concave lens B) Convex lens C) Cylindrical lens D) Plane lens 15.The image formed by a convex lens when the object is beyond 2F is: A) Real, inverted and diminished B) Virtual and erect C) Real and magnified D) Virtual and magnified 16.The power of a concave lens is: A) Positive B) Negative C) Zero D) Infinite 17.The principal focus of a concave mirror is: A) Behind the mirror B) At infinity C) In front of the mirror D) At the pole 18.The speed of light is maximum in: A) Water B) Glass C) Air D) Vacuum 19.A ray passing through the optical centre of a convex lens: A) Bends towards the principal axis B) Retraces its path C) Passes undeviated D) Reflects back 20.The mirror used in solar cookers is: A) Plane mirror B) Convex mirror C) Concave mirror D) Cylindrical mirror