Magnification

• 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

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.

• 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

• 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?