Consider a concave mirror of 10 cm focal length illuminated by an object kept at a distance of 25 cm. The distance at which the image is formed and its magnification respectively are

Options

A. `-1.67 cm and -0.67`
B. 7.1 and 0.29
C. `-16.7 cm and 0.67`
D. 7.1 cm and `-0.29`

Answer

A

Explanation

Using mirror equation, we have,
`(1)/(v) + (1)/(u) = (1)/(f)`
or `(1)/(v) = (1)/(f) - (1)/(u)`
`rArr (1)/(v) = (1)/((-10)) - (1)/((-25))`
[`:.` Given f `= - 10 cm, u = - 25 cm`]
`rArr v = -16.7 cm`
and magnification,
`m = -((v)/(u)) = (-(-16.7))/(-25) = - 0.67`