Question

An object is 15 cm away from a converging lens of focal length 10 cm. If it is placed then its image is formed on the screen. A diverging lens is placed in contact with the converging lens and due to this the screen has to be retracted 30 cm to obtain a clear image again. The focal length of the diverging lens​

Answer 1

Answer:

Given: f=−15

            v=−10

From mirror formula, v1−u1=f1

                                    −101−u1=−151

                                    u1=151−101

                                    u=−30 cm