Light rays from an object ：練習問題

Which of the following describes the correct path of light that allows a person to see a non-luminous object like a wooden desk?

A student uses a pinhole camera to observe a lit candle flame. Which of the following best describes the properties of the image formed on the translucent screen?

A student uses a pinhole camera to view the Sun (a circular luminous source). If the pinhole is triangular in shape and very small compared to the distance to the Sun, what will be the shape of the image observed on the translucent screen?

When you see a distant, non-luminous object like a mountain range on a clear day, which of the following best describes the path of light rays that allow you to see it?

In a dark room, a small torch is used to illuminate a green apple. A student stands at a position where they can see the apple clearly. Which of the following correctly describes the path of light rays that allows the student to see the apple?

You are in a completely dark room. When a torch is switched on, you can see a book on a table. Explain why the book becomes visible.

A small torch is placed in a completely dark room. If a tiny dust particle floats in the beam of light, explain why you can see the dust particle, even though it does not produce its own light.

A point light source is placed \(30\text{ cm}\) away from a vertical opaque rod that is \(12\text{ cm}\) tall. A screen is positioned parallel to the rod at a distance of \(60\text{ cm}\) behind the rod. Calculate the height of the shadow formed on the screen.

Explain how we are able to see a non-luminous object, such as a red apple, in a brightly lit room. Include the role of the light source, the object, and your eyes.

A student stands in a completely dark room. There is a luminous red LED and a non-luminous white ball on a table.

a) Explain why the student can see the red LED but cannot see the white ball. (2 points)
b) The student then turns on a torch and points it at the white ball. Describe the path of the light rays that now allows the student to see the ball. (2 points)