Question

An object is 30.0 cm form a spherical mirror, along the central axis.
The absolute value of lateral magnification is `1/2`, The image produced is inverted .
What is the focal length of the mirror?

Answer 1

Correct Answer - A::C
Image is inverted ,so it is real.u and v both are nagative, Magnification is `1/2`.
therefore, `v=(u/2)`
` Given , u=-30cm , v=-15 cm`
Using the mirror formula.
`1/v+1/u=1/f`
we have`1/f=1/(-15)-1/30=-(1)/(10)`
` :. f=-10cm.`