Question 7
Lenses and Optical InstrumentsIf u is the object distance and v the image distance, which of the following expressions gives the linear magnification produced by a convex lens of focal length f?
- A.u/v + f
- B.u/f − f
- C.v/f − 1
- D.v/f + 1
Show the answer and explanation
Answer: C (v/f − 1)
Explanation
From 1/u + 1/v = 1/f, multiplying by v gives v/u + 1 = v/f, so m = v/u = v/f − 1.