Question

An object is placed in front of spherical
mirror of focal length 20 cm
which form its image twice as size of object.
Find all possible values of object distance
image distance , nature of mirror and
image​

Answer 1

Answer:

An object is placed in front of a spherical mirror at a distance of 20cm from it. A virtual image is formed at a distance of 30cm from it. Arrange the following steps in the proper sequence to determine the nature and focal length of the mirror.

(a) Substitute the values of v and u in the mirror formula

f

1

=

u

1

+

v

1

(b) Check whether the focal length obtained is negative or a positive integer.

(c) Decide whether the mirror is a convex or a concave mirror based on the sign of the focal length obtained.

(d) Assign proper signs to the object distance and image distance by using the sign convention.

(e) Obtain the value of focal length.