Which type of the image is formed by the plane mirror?
a) real
b) virtual
c) both a and b
d) none of them
Which of the following is an optical device?
a) thermometer
b) periscope
c) sphygmomanometer
d) none of these
A periscope is
an optical device that uses.…… to reflect images through a tube?
a) concave lenses
b) mirrors
c) convex lenses
d) all of these
What is the angle between two mirrors in the simple periscope?
a) 30
b) 45
c) 60
d) 90
How many times the light rays coming from the object behind obstacle are reflected in periscope?
a) two
b) three
c) four
d) five
How many plane mirrors are used in the simple periscope?
a) two
b) three
c) four
d) five
