Q.1
What is the SI unit for the power of the lens?
  • a) Watt
  • b) Dioptre
  • c) Meter
  • d) Centimeter
Q.2
The lens power is 1D, what will be its focal length in centimeter?
  • a) 100
  • b) 0.91
  • c) 0.1
  • d) 10
Q.3
Name the lens used in a simple microscope.
  • a) Biconvex
  • b) Biconcave
  • c) Plano-convex
  • d) Cylindrical
Q.4
If the magnification is positive and greater than unity, what does it indicate?
  • a) Virtual image
  • b) Real image
  • c) Distorted image
  • d) Erect image
Q.5
What will be the power of convex lens having focal lengthcm?
  • b) -2 D
  • c) +50 D
  • d) -6 D
  • a) +2 D
Q.6
What will be the focal length of a convex lens having power -1.5 D?
  • a) -66.66 cm
  • b) +66.66 cm
  • c) +1.5 cm
  • d) -1.5 cm
Q.7
How will be the image formed, when an object is placedcm from a convex lens, whose focal length iscm?
  • a) Virtual and enlarged
  • b) Virtual and reduced in size
  • c) Real and enlarged
  • d) Real and reduced in size
Q.8
At what distance the object should be placed, when convex lens is used as simple magnifying glass?
  • a) Less than one focal length
  • b) Less than twice the focal length
  • c) More than one focal length
  • d) More than twice the focal length
Q.9
What type of image is produced by a concave lens?
  • a) Always virtual and enlarged
  • b) Always real
  • c) Always virtual and reduced in size
  • d) Sometimes real and sometimes virtual
Q.10
At what distance the image will be formed when an object is placedcm from a convex lens whose focal length iscm?
  • a) 50 cm
  • b) 5.66 cm
  • c) 6.66 cm
  • d) 16.66 cm
Q.11
What is the least distance for distinct vision?
  • a) 25 m
  • b) 25 cm
  • c) 25 mm
  • d) 2.5 cm
Q.12
A ray of light travels from a medium of refractive index m1 to a medium of refractive index mIf “i” and “r” are the angle of incidence and refraction, then what is sin(i)/sin(r)?
  • a) m1
  • b) m2
  • c) m12
  • d) m21
0 h : 0 m : 1 s