Which of these are used in astronomical laboratories?
Compound microscope
Telescope
Photographic camera
Magnifing glass
Which of these lens are used for image formation in human eye?
Concave lens
Convex lens
Both concave and convex lens
None of these
The unability of human eye to see nearly objects
Short sightedness
Real image
Virtual image
Long sightedness
Light travelling from a denser medium to a rarer medium along a normal to the boundary"
is refracted towards the normal
is refracted away from the normal
goes along the boundary
is not refracted
Focal length of convex lens is
1/2 radius of curvature
2 x radius of curvature
equal to radius of curvature
4 x radius of curvature
The unability of human eye to see faraway objects
A diverging lens is used in :
a magnifying glass
a car to see objects on rear side
spectacles for the correction of short sight
a simple camera
Phenomenon of bending of light when it travels from one medium to another is
Interference
Refraction
Dispersion
Diffraction
A young man has to hold a book at arm's length to be able to read it clearly. The defect of vision is :
astigmatism
myopia
presbyopia
hypermetropia
Which one of the following materials cannot be used to make a lens?
Water
Glass
Plastic
Clay
