Q.1
The power of a lens (SI system) can be calculated using which of the following formulae?
  • Power = 1 / focal length (in m)
  • Power = focal length / 1
  • Power = 1 / focal length (in cm)
  • Focal length (m) = 1 / Power2
Q.2
In the eye, which of the following parts does light NOT travel through?
  • The pupil
  • The lens
  • The cornea
  • The iris
Q.3
A lens which focuses light to a point is called a what?
  • A converging lens
  • A diverging lens
  • A meniscus lens
  • A biconvex lens
Q.4
What is the unit of power for a lens?
  • Watt
  • Joule
  • Dioptre
  • Metre
Q.5
What part of the eye focuses the light?
  • The lens
  • The iris
  • Suspensory ligament
  • Retina
Q.6
What is chromatic aberration?
  • Where light is split into constituent colors as it travels through a lens
  • Separate rays of colored light are converged into one beam of chromatic light
  • Where chromatic light is split into two colors after traveling through a lens
  • Chromatic aberration does not affect light
Q.7
What is the focal length of a lens which has a power of 0.5?
  • 2 cm
  • 2 m
  • 0.2 m
  • 0.5 m
Q.8
What is the power of a lens dependent on?
  • The type of wave incident on the lens
  • The focal length of the lens
  • The time of day
  • The way the lens is being held
Q.9
What is the power of lens which has a focal point of 20 cm?
  • 0.05
  • 0.5
  • 5
  • 50
Q.10
Calculate the power of a converging lens of focal length 0.05 m.
  • 20
  • -20
  • -2
  • 2
0 h : 0 m : 1 s