An object is placed 12 cm from a concave (converging) mirror with a focal length of 6 cm. Where is the image formed?
A4 cm in front of mirror
B6 cm in front of mirror
C12 cm in front of mirror
D18 cm behind mirror
Explanation
📌 1/d_o + 1/d_i = 1/f. 1/12 + 1/d_i = 1/6. 1/d_i = 1/6 − 1/12 = 2/12 − 1/12 = 1/12. So d_i = 12 cm in front. Distractor A: wrong reciprocal; B: reported f; D: wrong side.