Question 3
Lenses and Optical InstrumentsA person can focus an object only when it lies within 200 cm from him. Which spectacles should be used to increase his maximum distance of distinct vision to infinity?
- A.concave lens
- B.plane glasses
- C.binoculars
- D.convex lens
Show the answer and explanation
Answer: A (concave lens)
Explanation
He is short-sighted (far point 200 cm). A diverging (concave) lens makes rays from distant objects seem to come from within his far point.