Question

5. Find the position, size and the nature of the image formed by a spherical mirror from the following data. u = -20 cm, f= -15 cm, h. = 1.0 cm​

Answer 1

Given :-

u = -20cm

f = -15cm

h = 1 cm

By using mirror formula :-

$\frac{1}{f} \: = \frac{1}{u} + \frac{1}{v} \\ \\ \frac{1}{v} = \frac{1}{f} - \frac{1}{u} \\ \\ \frac{1}{v} \: = \frac{1}{ - 15} - \frac{1}{ - 20} \\ \\ \frac{1}{v} = \frac{4 - 3}{ - 60} \\ \\ \frac{1}{v} = \frac{1}{ - 60} \\ v \: = - 60 \\ \\ the \: image \: is \: formed \: at \: a \: distance \: 60cm \\ \: on \: the \: left \: side \: of \: the \: mirror \: from \: the \: point \: .$

m = h' / h = -v/u

h' = -1× -60/-20

h' = -3cm .

The image size is 3cm and therefore it is real and inverted .

Hence ,

Position :- On the left side of the mirror

from the point.

Size :- 3cm

Nature :- Real & inverted .