Q.41)-Electron microscope is more magnifier than light magnifying because
  • Velocity of electron is less than velocity of light
  • Wavelength of electron is less than the wavelength of light
  • Electron contains more energy than particles
  • More powerful lenses are used in electron microscope
Q.42)-A periscope works on the principle of
  • Refraction
  • Total internal reflection
  • Diffraction
  • Reflection
Q.43)-In mirrors the back surface is painted with a thin layer of
  • Mercury
  • Silver
  • Red oxide
  • Silver nitrate
Q.44)-Which of the following is used to split white light into different colours?
  • Glass slab
  • Convex lens
  • Concave lens
  • Prism
Q.45)-Spectacles used for viewing 3D films have
  • Bifocal lens
  • Convex lens
  • Concave lens
  • Polaroids
Q.46)-A concave lens always form an image which is
  • Real and erect
  • Virtual and erect
  • Real and inverted
  • Virtual and inverted
Q.47)-One can distinguish a telescope from a microscope by observing
  • Length
  • Colour
  • Size of the lens
  • Length and size of the lens
Q.48)-To get the magnified and virtual image mirror is used
  • Plane mirror
  • Convex mirror
  • Concave mirror
  • Concave lens
Q.49)-Which of the following always makes the smaller image of body, which is played in front of it?
  • Plane mirror
  • Convex mirror
  • Convex lens
  • Concave mirror
Q.50)-The image formed by specific mirror; legs appears as of same size but head and his body appears smaller than its real size, when person stands in front of mirror. What is the nature of mirror?
  • Plane and concave
  • Convex and concave
  • Convex and plane
  • Plane