An object is placed 30 cm from a convex lens of focal length 10 cm. At what distance from the lens is the image formed?
Answer and explanation
Correct answer: D. 15 cm
- Step 1: With and : , so cm. Answer: 15 cm. Why not the others: 7.5 cm: uses a plus sign in the denominator. 40 cm: adds the object distance and focal length. 10 cm: gives the focal length.
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