Question

An object and a screen are fixed 80 cm apart. In one position, for a convex

lens a real image is formed on the screen with a magnification of 2/3. Find the

focal length of the lens.​

Answer 1

Answer:

- 1.6m

Explanation:

we have u= -0.8 and m= 2/3 so m= v/ u=h2/h1

1/f= 1/v-1/u

the focal length become

- 1.6 m