# Converging Lenses

A converging lens has a focal length of 30 cm. An object that is 20 cm tall is placed 45 cm from the lens.

1. What is the image distance?

a. 45 cm, other side of lens

b. 20 cm, same side of lens

c. 100 cm, other side of lens

d. 30 cm, same side of lens

2. Is the image upright or up-side-down?

3. How tall is the image?

4. Two waves interfere. When a crest of wave "G" that is 4 cm tall passes through a trough of wave "J" that is -5 cm deep. The resulting wave has an amplitude of ___.

A. -20cm

B. 0cm

C. -1cm

D. +1cm

https://brainmass.com/physics/lenses/converging-lenses-19272

#### Solution Preview

1.)

focal length of the lens = 30 cm

distance of the object from the lens (u) = -45 cm

(Here -ve sign for sign convention that, if the object is real the distance is taken to be -ve)

distance of ...

#### Solution Summary

The solution uses the relevant formulae to calculate the answers as well as providing explanations derived from the relevant theory on images and converging lenses.