Two thin lenses of powers +12 D and -2 D are placed in contact coaxially. An object is placed at a distance of 15 cm from this combination. The linear magnification produced by the combination is

Step-by-step solution

Effective power of the combination, P_ net = P₁ + P₂ P_ net = +12 D + (-2 D ) = +10 D Effective focal length, f_ net = 100 P_ net cm = 100 10 cm = +10 cm Given object distance, u = -15 cm (using sign convention) Using the formula for linear magnification in terms of focal length and object distance: m = f_ net f_ net + u m = 10 10 + (-15) = 10 -5 = -2 Thus, the linear magnification produced is -2 . Answer: -2