Application of converging lens

Magnifying glass

For a magnifying glass to work, the object is placed at the focal point such that the image produced is magnified, upright and virtual.

• With the naked eye alone, the eye sees by focusing at its near point.
• Through a magnifying glass, the eye sees by focusing also at its near point, but now the image is enlarged.
• Generally, your eyes only allow you to see objects clearly when the distance of the object from your eyes is more than 25 cm. However, a magnifying glass will allow the objects’ placements to be closer than 25 cm when the image is at least 25 cm away from the eye.

Projector

Projector is used to produce an enlarged, real and inverted image of an object just beyond the focal length of a thin converging lens and the image can be projected onto a screen.

• Image formed will be laterally and vertically inverted. Hence, the transparency has to be put left to right and in a upside down position for the image to be the right side up.
• The transparency is placed close to the focal point of the lens.