An object is placed 10 cm from a convex lens with a focal length of magnitude 20 cm. What is the magnification?
A) 2.0
B) -2.0
C) 1.5
D) 0.50
E) -2.5

Question

Quizplus · Accepted Answer

The magnification (M) of a lens is given by the formula M = -v/u, where v is the image distance and u is the object distance. First, we need to find the image distance using the lens formula 1/f = 1/v + 1/u, where f is the focal length. Given f = 20 cm and u = -10 cm (object distance is taken as negative in lens formula), we can solve for v. Substituting the values, we get 1/20 = 1/v - 1/10. Solving for v gives v = 20 cm. Therefore, the magnification M = -v/u = -(20)/(-10) = 2.0.

An Object Is Placed 10 Cm from a Convex Lens