Final answer:
The magnification of the object placed in front of a concave lens is 2.
Step-by-step explanation:
To find the magnification of an object placed in front of a concave lens, we can use the formula m = -di/do, where m is the magnification, di is the image distance, and do is the object distance. In this case, the object is 3 cm in front of the lens and the focal length of the lens is 2 cm.
Using the thin lens formula, 1/f = 1/do + 1/di, we can calculate the image distance. Plugging in the values, we get 1/2 = 1/3 + 1/di. Solving for di, we find that di = -6 cm. Since the magnification is equal to -di/do, the magnification in this case is 2.