The image obtained on the screen of a pin-hole camera becomes less sharply defined when the

Analyze the question: A pin-hole camera forms an inverted image on a screen. We need to find which change makes the image blurry (less sharp).

Concept: Each point on the object sends a narrow cone of light through the pin-hole. On the screen, this cone makes a small spot, not a perfect point. The size of that spot depends on the size of the hole.

• A small hole gives small spots, so the image is sharp (but dim).
• A larger hole gives bigger overlapping spots, so the image is blurred.

Checking each option:

• A. Object moved farther away: The image becomes smaller, but it stays sharp. (It actually gets slightly sharper, since the light cone is narrower.)
• B. Screen moved farther from the pin-hole: The image becomes larger and dimmer. The blur spots also grow in proportion, but the image stays reasonably sharp. This is not the main cause of loss of sharpness.
• C. Object made smaller: The image is smaller, but sharpness is unaffected.
• D. Illumination more intense: The image is brighter, with no loss of sharpness.
• E. Pin-hole made larger: More light passes through from each object point, and the spots on the screen overlap more. The image becomes less sharply defined. ✔

Answer: The correct option is E.

Tip: Remember "Small hole = sharp but dim; big hole = bright but blurry." In pin-hole camera questions, sharpness is almost always about the size of the aperture.