Optics Answers

The image of a child standing in front of a flat mirror is
erect and virtual
erect and real
inverted and virtual
inverted and real

What is the difference between a real and a virtual image?
a)A real image is always erect; virtual image can be inverted
b)A real image is bigger than the object; a virtual image can be smaller
c)Light comes from a real image; it only appears to come a virtual one
d)There is no difference; what you get depends only on the type of mirror

The focal length of a curved mirror is ---------- the radius of the spherical surface
a)twice
b)equal to
c)half
d)one-quarter

An object placed in front of a convex mirror of radius 20cm produces an erect image which is one-fifth the size of the object. How far is the object from the mirror?
20 cm
30 cm
40 cm
50 cm

How far should an object be from a concave mirror of radius 30cm to form a real image 1/6 of its size?
85 cm
95 cm
105 cm
115 cm

What is the image distance of an object placed 20 co from a converging lens of focal length 15 cm?
30 cm
40 cm
60 cm
70 cm

A ray of light enters into glass slab from air of incident angle 60° if refractive of glass slab is give by A-BT where A and B are constant and t is the thickness of slab measured from the top surface.find the maximum depth travelled by ray in the slab.assume thicknesses of slab to be sufficiently large?

A ray R1 is incident of the plane surface of the glass slab (kept in air) of refractive index √2 at angle of incidence equal to the critical angle for this air glass system.the refractive ray R2 undergoes partial reflection and refraction at the other surface.find the angle between reflected ray R3 and the refracted ray R4 at the surface?

What is the reason we can read print from any direction?

A lens which is thinnner at centre than at the edge is a _______________ lens