Properties of Light and Related Phenomena: แบบฝึกหัด

Which of the following objects is considered an artificial source of light?

A periscope is an instrument often used in submarines or by people to see over obstacles. Which property of light is primarily used to make a periscope work?

Two plane mirrors are placed at a right angle (\(90^\circ\)) to each other. If a ray of light hits the first mirror at an angle and then reflects off the second mirror, what will be the final direction of the light ray?

The Moon appears to change its shape (phases) when viewed from Earth throughout a month. What is the primary reason for this change in appearance?

Dentists often use a special mirror to see a magnified (larger) and clear image of a patient's teeth. Which type of mirror is used for this purpose?

When a stick is placed vertically on a flat playground on a clear sunny day, the length and position of its shadow change throughout the day. What causes the length of the shadow to be the shortest at noon compared to early morning?

When using a magnifying glass to look at an object, the object appears much larger. Explain the role of refraction and the specific shape of the convex lens in creating this magnified effect.

A student stands in front of a vertical plane mirror to observe his own reflection.

(a) State the relationship between the size of the student and the size of his image in the mirror. (1 point)

(b) If the student stands exactly \( 2 \) meters away from the mirror surface, what is the total distance between the student and his image? (1 point)

(c) The student raises his left hand, but his reflection appears to raise its right hand. What is the name of this phenomenon? (2 points)

A student places a coin at the bottom of an empty, opaque plastic bowl. He stands at a position where the coin is just hidden from his view by the edge of the bowl.

(a) Explain why the student cannot see the coin at this position, referring to a specific property of light. (1 point)
(b) As water is slowly poured into the bowl, the student observes that the coin gradually "reappears" even though he has not moved. Identify this phenomenon and explain how the change in the light's path makes this possible. (2 points)
(c) If the student replaces the coin with a small plane mirror at the bottom of the bowl, describe two characteristics of the image of an object held above the bowl as seen in the mirror. (2 points)
(d) If a beam of white light is shone into the water at an angle, it can sometimes be seen separating into different colors. Name this process and explain why different colors of light separate when they move from air into water. (2 points)