Question

when a concave mirror is placed facing the sun the sun's rays converge to a point 10 cm from the mirror now when erect 2 cm long penis placed 15 CM Away on the principal axis of the mirror if you want to get an image of the pin on a card where would you place the card what would be the nature and height of the image ?

Answer 1

The rays converging in case of sun is at the focus. Thus the focus is at 10 cm. 
Now your object is placed between focus and centre of curvature in front of a concave mirror so the image formed would be inverted and real. To find the height use following formula-
$\frac{height of image}{height of object}= \frac{focal length}{focal length-object distance}$
=$\frac{height of image}{2}= \frac{-10}{-10+15}$
=$\frac{height of image}{2} = \frac{-10}{5}$
=$height of image= -2*2=-4 cm$

Answer 2

answer is 2 cm
I think