To determine the approximate value of the focal length of a given concave mirror, you focus the image of a distant object formed by the mirror on a screen. The image obtained on the screen, as compared to the object is always :

(a) Laterally inverted and diminished

(b) Inverted and diminished

(c) Erect and diminished

(d) Erect and highly diminished

An illuminated object is placed at a distance of 20 cm from a converging lens of focal length 15 cm. The image obtained on the screen is : (a) upright and magnified (b) inverted and magnified (c) inverted and diminished (d) upright and diminished

The image formed by a concave mirror is real, inverted and highly diminished (much smaller than the object). The object must be : (a) between pole and focus (b) at focus (c) at the centre of curvature (d) at infinity