MYP Physics · 11 · extended response
Design a low-cost image projector
Light and optics · Original GioPhysics question with a detailed, mark-by-mark answer guide.
- Demand
- discriminating
- Marks
- 7
- Topics
- 2
- Answer
- Complete
A youth centre wants to project a phone screen onto a wall using a converging lens and a cardboard box. The design must be inexpensive, safe, and usable in a room that cannot become completely dark.
- a
Explain Explain where the phone should be placed relative to the lens focal length to form a real enlarged image on the wall.
2 marks - b
Propose Propose two practical design features that would make the projected image easier to use.
2 marks - c
Evaluate Evaluate whether this projector is a suitable replacement for a commercial classroom projector in the stated room.
3 marks
Ready to self-mark?Reveal the detailed answer guide
a
Explain Explain where the phone should be placed relative to the lens focal length to form a real enlarged image on the wall.
Build a chain of claim, evidence and physics reasoning. Address more than one relevant factor, identify a limitation or assumption, and finish with a conclusion that is conditional on the evidence rather than absolute.
- 1
Places the phone beyond one focal length from the converging lens so that a real image can form.
- 2
Places it between one and two focal lengths for an enlarged real image, with the image inverted.
b
Propose Propose two practical design features that would make the projected image easier to use.
Build a chain of claim, evidence and physics reasoning. Address more than one relevant factor, identify a limitation or assumption, and finish with a conclusion that is conditional on the evidence rather than absolute.
- 1
Proposes a focusing adjustment by sliding the phone, lens, or box sections while keeping them aligned.
- 2
Proposes another defensible feature such as rotating the phone display, shielding stray light, using a matte white screen, or ventilating the phone.
c
Evaluate Evaluate whether this projector is a suitable replacement for a commercial classroom projector in the stated room.
Build a chain of claim, evidence and physics reasoning. Address more than one relevant factor, identify a limitation or assumption, and finish with a conclusion that is conditional on the evidence rather than absolute.
- 1
Uses a benefit such as low cost, repairability, or accessible construction.
- 2
Uses a physics-based limitation such as low brightness, reduced contrast in ambient light, optical distortion, or limited focus.
- 3
Gives a justified conclusion linked to the youth centre's conditions rather than a simple yes or no.
Private on this device