Magnification

This experiment allows the students to observe and calculate magnification using convex lenses. As a further exercise, students investigate the dioptric power of the lens.

40 min

Light and optics

magnification; image formation; lenses

What students learn

To experience the nature of magnification with a real image formed on a screen, and relate it to practical applications
To study and understand the concept of the dioptric power of a lens

The science behind this experiment

Parallel wave-front (or plane wave-front). A wave-front is plane when light neither diverges nor converges but runs in a straight line (like laser beams).

Inversion of image.: Object is the illuminated image (pinhead in our case), Real image is the image seen on the screen. The image will always be upside-down.

Magnification. Image is magnified or reduced depending on the position of the lens: if we move the lens further away from the pinhead we’ll see the image reducing; if we move the lens closer, we’ll see it enlarging.

Equipment used

Inclined plane with 3 different track terminals — 5491.11
Projector with 12 V 20 W halogen lamp — 4414.18
Slider for holders — 4417.01
Slider for Projector — 4414.17
Holder for slides and diaphragms — 4414.03
Holder for 50mm diameter lenses and mirrors — 4414.02
Pinhead slit (set of seven diaphragms) — 4414.12
Set of 4 Biconvex spherical lenses, f: 5, 10, 15, 20 cm — 4445.00
White metal screen, squared 140 mm, 10 mm diameter support — 4418.35

Chemicals and reagents

Safety notes

Questions for students

What precautions should you observe when measuring the distances required for this experience?
How would you describe the image formed with a convex lens?
Is the image always magnified?
What is the value of magnification when the image has the same size as the object? Which position of the object makes this condition occur?

What to expect

Make sure there is no parallax error when measuring the distance from the lens to the screen and from the object to the lens.

Disposal

Run this experiment in your classroom

This experiment is part of the ATP Mobile Lab — a self-contained laboratory that turns an ordinary classroom into a working science lab, with over 200 experiments in physics, chemistry, biology, robotics and engineering. Gali, the AI tutor built into ATP Connect, guides students through each step and answers their questions at the bench.

See the Mobile Lab Talk to our team