When two lenses are placed in contact, the focal length of the combination is equal to the sum of the focal lengths of the lenses.
  • True
  • False
A ray of light travelling in air falls obliquely on the surface of a calm pond. It will
  • deviate towards the normal
  • go into the water without deviating from its path
  • deviate away from the normal
  • turn back of its original path
If a ray of light passes from vacuum to a transparent medium, it will bend away from the normal.
  • True
  • False
The central portion of a thin lens behaves like a rectangular slab
  • True
  • False
A convex lens forms a virtual image when an object is placed at a distance of 18cm from it. The focal length must be
  • less than 36cm
  • greater than 36cm
  • greater than 18cm
  • less than 18cm
A thin lens and a spherical mirror have a focal length of $+15cm$ each.
  • Both are concave
  • Both are convex.
  • The lens is convex and the mirror is concave
  • The lens is concave and the mirror is convex
An object is placed before a concave lens. The image formed
  • is always erect
  • is always real
  • is always inverted
  • may be erect or inverted
The angle of reflection is the angle between
  • the normal to the surface and reflected ray.
  • the reflected ray and the surface of the mirror
  • (i) and (ii)
  • None of the above
A light ray enters from medium A to medium B as shown in figure. The refractive index of medium B relative to A will be
  • greater than unity
  • less than unity
  • equal to unity
  • zero
Beams of light are incident through the holes A and B and emerge out of box through the holes C and D respectively as shown in the figure. Which of the following could be inside the box?
  • A rectangular glass slab
  • A convex lens
  • A concave lens
  • A prism
Which of the following ray diagrams is correct for the ray of light incident on a concave mirror as shown in figure?
  • Fig. A
  • Fig. B
  • Fig. C
  • Fig. D
Which of the following ray diagrams is correct for the ray of light incident on a lens shown in figure?
  • Fig. A
  • Fig. B
  • Fig. C
  • Fig. D
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