Question

(C) (+x)2
(d) x/x,
speed of
will be
MI FONT a
The image formed by a convex mirror of focal length 30 cm
is one quarter of the size of object. The distance of object
form the mirror is
(a) 30 cm
(c) 90 cm
(b) 120 cm
(d) 60 cm
​

Answer 1

Answer:

(a)30cm is your answer

Answer 2

The focal length of the convex mirror is f=30cm and the magnification of the image is m=1/4

We have to calculate the object distance u.

According to sign convention, the measurements along the direction of light are taken as positive and opposite to the light taken as negative. The transverse measurement above the principal axis is taken as positive and below the principal axis is taken as negative.

Thus, f=+30cm and m=+1/4=+0.25

Using formula, m= f/f-u

or mf−mu=f

or u= mf−f/m = m−1/m f= 0.25−1/0.25(30)=−90cm

Explanation:

Hope this answer will be helpful..