An object is placed before a convex mirror (as shown in the ray diagram). If the object is brought closer to the mirror, the image _______ in size.   decreases   increases   To obtain an erect and magnified image, the object must be placed before a concave mirror between _______.   the principal focus and the center of curvature   the pole and the principal focus   the center of curvature and infinity   Hint Half-n-half Clue   The geometric center of the curved mirror is called _______.   centre of curvature   principal axis   pole   Half-n-half Clue   If the radius of curvature of a spherical mirror is 20 cm, then its focal length is _______ cm.   40   10   20   Half-n-half Clue   _______ mirrors are used as reflectors in flashlights and automobile headlights.   convex   concave