Question

If an object is placed at a distance of 10 cm in front of a concave mirror of focal length 4 cm, find the position and characteristics of the image formed. Also, find the magnification.

Answer 1

Answer:

Explanation:

Focal length f = - 4 cm

Object distance u = - 10 cm

v , image distance = ?

Mirror formula

$\frac{1}{v} +\frac{1}{u} = \frac{1}{f}$

Putting the given values

$\frac{1}{v} - \frac{1}{10} = - \frac{1}{4}$

$\frac{1}{v}= - \frac{3}{20}$

v = - 6.67 cm .

magnification

m = v / u

= - 6.67 / - 10

= .667

so image will be smaller in size in comparison with size of object .

Characteristics will be that ,

1 ) it will be inverted and

2 ) it will be real image .