Try it yourself
Question
The full-scale diagram below shows a converging lens and an object. Each principal focus is marked with an F:
- Draw two rays to find the position of the image. Label the image I. Draw arrows on each ray to show its direction.
- The magnification of an image, M, is defined by the equation: \(\frac{\text{height of image}}{\text{height of object}}\). Calculate the magnification of the image in your ray diagram. Show your working out clearly.
- Is the image real or virtual? Explain your answer.
- State an application for a lens in this way.
2.
- Height of object = 1.6 cm
- Height of image = 2.5 cm
- M = \(\frac{\text{height of image}}{\text{height of object}}\)
- M = \(\frac{\text{2.5 cm}}{\text{1.6 cm}}\)
- M = 1.6
- The magnification is 1.6.
3. The image is real. Actual rays of light pass through the image. It can be projected on a screen.
4. The image is real, inverted and enlarged. An application for a lens used in this way is a cinema projector.