You want to build a projector to display a happy face on a w

You want to build a projector to display a happy face on a wall. You put together something that resembles the following: A light source at A, a happy face transparency slide at B, a lens at C, and a wall at D. Ideally, you will want to package the light, happy face and lens all in one box. You decided to pick a converging lens with a focal length of 50mm. The distance between the happy face and the lens is 6.0cm. Where is the image located? Is it right side up or upside down? How much bigger is it? Where do you place the happy face so that the projection is exactly twice the original size? Draw a principal ray diagram. Include the optical axis, the p, f, and c rays. Label the object and image distances. Indicate whether the image is real or virtual. Please draw it to scale as best as possible.

Solution

At 30cm on the other side of the lense. It is upside down. It is five times bigger than the happy face b) At the distance of 7.5 cm from the lense c)

A ray diagram is the simle one obtained by placinf the object at the distance of 6cm from the lense of focal length 5cm with the real inverted image at the distance of 30 cm on the other side of gthe lense.