Question

An object placed 45 cm from a lens forms an image on the screen placed 90 cm on the other side of the lens. Identify the type of the lens and its focal length.

Answer 1

Pls check this ans. bro if it is correct pls tell me also

Answer 2

It's convex lens...

1/f=1/v-1/u

By applying sign convention,

1/f=1/90+1/45

1/f=1+2/90

1/f=3/90

1/f=1/30

f=30 cm