Images on the Axis

Why it matters

One mirror: dentist's magnifier, shaving mirror, torch reflector and solar cooker. Nobody changes the mirror — they only change where things STAND.

The idea in plain words

The positions and their prizes. Tap them.

where it stands → what you get

Why does a torch put its bulb AT the focus of its concave reflector?

The reflector turns a glow into a beam

• case 1: far away — image small, inverted, near F — how telescopes collect
• case 2: between C and F — image large, inverted, beyond C — the projector zone
• case 3: inside F — image virtual, upright, magnified, behind the mirror — dentist & shaving territory
• the jobs: uses — concave: torch, headlamp, solar cooker, doctor's head mirror · convex: rear-view (wide, erect)
• Rays from F reflect parallel
• Parallel beam = light that carries

Predict first

To see your face magnified and UPRIGHT in a concave mirror, hold it…

Inside F is the only zone with a virtual, erect, magnified image — every make-up and shaving mirror is used there.

• close — your face inside the focus — correct
• far beyond C
• anywhere — concave always magnifies

What you do

Walk the candle from far away to inside the focus — watch the image flip, grow, and finally jump behind the mirror.

Check yourself

A convex mirror always shows…

The one-trick mirror: shrink and survey — exactly what a rear-view needs.

A dentist's mirror is…

Inside F: upright and magnified — the only useful view of a molar.

For a solar cooker, the pot sits…

Parallel sun-rays all report to F — lunch is served at the focal point.

• a smaller, upright image — with a wide view — correct
• a magnified image
• an inverted image
• concave, held closer than its focal length to the tooth — correct
• convex
• plane
• at the mirror's focus, where sunlight concentrates — correct
• at the pole
• behind the mirror