Question

A `2.0 cm` tall object is placed `15 cm` in front of concave mirrorr of focal length `10 cm`. The size and nature of the image will be
A. `1.0 cm, `real
B. `4 cm, `virtual
C. `4 cm`, real
D. none of these

Answer 1

Correct Answer - C
Using to mirrorr formula, `(1)/(v)+(1)/(u)=(1)/(f)`
`(1)/(v)=(1)/(f)-(1)/(u)=(1)/(-10)-(1)/(-15)=(1)/(-10)+(1)/(15)`
or `v=-30 cm`
The image is formed at a distance of `30 cm` from the mirrorr on the same side of the object. It is a real image.
Lateral magnification of the concave mirrorr,
`m=(-v)/(u)=(h_(1))/(h_(o))`
`(-(30))/(-15)=(h_(1))/(2)impliesh_(1)=-4 cm.`
Negative sign shows that image is inverted.
The image is real, inverted, of size `4 cm` at a distance of `30 cm` in front of the mirrorr.