NCERT Solutions Curiosity Chapter 11 .7 Pinhole Camera — Activity 11.9: Let us explore
Book page 16311 Updated on2026-09-05
Q1.
What do you see on the screen? Do you notice anything surprising?
Answer
On the screen we see a small, faint image of the candle flame. The surprising part is that the image is upside down — it is inverted. The tip of the flame in the image points downwards.
Light from the top of the flame goes down through the pinhole and lands low on the screen; light from the bottom goes up and lands high. The rays cross at the hole, so the image is inverted.
Why it happens: Light travels in straight lines, and only the rays that pass through the tiny hole reach the screen. The straight ray from the top of the flame can only continue downwards after the hole, and the ray from the bottom of the flame can only continue upwards. Since the two rays cross each other at the pinhole, top and bottom are exchanged and the image comes out upside down.
Tip: Make the hole smaller and the image gets sharper but dimmer; make it bigger and the image gets brighter but blurred.