Question

A 5cm tall object is placed 4cm in front of a converging lens that has a focal length of 8cm. Where is the image located in _____ cm? a. -8 cm b. -4 cm c. -5 cm d. -2 cm

Answer 1

Answer:

a. -8 cm

Explanation:

$d_{o}$ = distance of the object = 4 cm

$d_{i}$ = distance of the image = ?

$f$ = focal length of the converging lens  = 8 cm

using the lens equation

$\frac{1}{d_{o}} + \frac{1}{d_{i}} = \frac{1}{f}$

$\frac{1}{4} + \frac{1}{d_{i}} = \frac{1}{8}$

$d_{i}$ = - 8 cm