Rohit claims to have obtained an image twice the size of object with a concave lens. Is he correct?
An object 2 cm high is placed at a distance of 16 cm from a concave mirror which produces a real image 3 cm high. Find the position of the image.
A real image, 4/5 size of the object is formed 18 cm from a lens. Calculate the focal length of the lens,

Explanation

No, Rohit is incorrect because magnified image of an object cannot be formed by a concave lens ever.
Object height, h=+2 cm
Image height , h.=-3cm (real image is inverted)
v=?
m=h./h=-v/u
v=-24 cm
image is formed at a distance of 24 cm in front of the mirror.
3. v=+18 cm
h/h=-4/5
m=h./h=v/u
v/u=-4/5
4u=-5v
Therefore, u=-22.5 cm