Which
of the following act like diaphragm of camera………
a)
Lens
b) Cornea
c) Iris
d) Retina
A person suffering from short sightedness cannot see………objects clearly but can see the ………….objects clearly.
a) nearby, far off
b) far off, nearby
c) nearby, nearby
d) far off, far off
Short sightedness can be corrected by wearing spectacles having …………..of suitable focal length.
a) concave lenses
b) convex lenses
b) both a and b
d) none of these
A
person suffering from long sightedness cannot see the ……object clearly but ………
objects can be seen clearly.
a) near, far off
b) far off, near
c) near, near
d) far off, far off
Long sightedness defect can be removed by wearing having …….of suitable focal length.
a) concave lenses
b) convex lenses
b) both a and b
d) none of these
What is the lens?
a) An image – forming device
b) An image – producing device
c) An image – reflecting device
d) An object – reflecting device
