An object is placed 7.2 cm in front of a thin lens, and its image forms 8.0 cm f
ID: 1486714 • Letter: A
Question
An object is placed 7.2 cm in front of a thin lens, and its image forms 8.0 cm from the lens on the opposite side of the object. Is the lens converging or diverging, and what is its focal length f?
converging, f = 3.8 cm
converging, f = 12 cm
diverging, f = -3.8 cm
converging, f = 72 cm
An object is placed 7.2 cm in front of a thin lens, and its image forms 8.0 cm from the lens on the opposite side of the object. Is the lens converging or diverging, and what is its focal length f?
converging, f = 3.8 cm
converging, f = 12 cm
diverging, f = -3.8 cm
converging, f = 72 cm
Explanation / Answer
use the thin lens equation to find the focal length,
1/f = 1/do + 1/di
1/f = 1/7.2 + 1/8
f = 3.8 cm,converging lens