Olympiad Test: Light, Shadows And Reflection - 1 - Class 6 MCQ

Luminous objects which produce their own light.
For ex. Sun , etc.

Shadows change size during the day because of the position of the Sun. When the Sun is overhead shadows are short. At dusk and at dawn shadows are long.

- When a letter is viewed in an ordinary plane mirror, it undergoes a lateral inversion, meaning it is flipped horizontally.
- The capital letter "R" in a mirror will have its right side become the left and vice versa.
- Option B shows the letter "R" flipped horizontally, which is the correct mirrored image.
- Lateral inversion does not change the vertical orientation, so the top and bottom remain unchanged.
- Therefore, the correct mirrored appearance of "R" is as shown in option B.

- When an object is viewed in water, the image appears erect because:
- Light reflects off the object and travels through water to reach our eyes.
- The water surface acts like a plane mirror.
- Plane mirrors always form images that are laterally inverted but upright.
- Therefore, the image formed is upright and appears at the same height as the object, hence it is erect.Correct option is C. Erect

- Ishani observes the sun's position changing because of the Earth's rotation.
- The Earth rotates on its axis from west to east, completing a full rotation in about 24 hours.
- This rotation causes the sun to appear to rise in the east, move across the sky, and set in the west.
- This daily movement gives us day and night.
- The rotation of the Earth, not its revolution around the sun or any other celestial body, is responsible for this observation.

- To form a circular shadow, an object must have a circular cross-section when light is shone onto it.
- A CD and a ball both have circular cross-sections, so they can form circular shadows.
- An ice-cream cone can cast a circular shadow if the light hits its base perpendicularly.
- A shoe box, with its rectangular shape, will predominantly cast rectangular or elongated shadows, not circular ones.
- Therefore, a shoe box (B) will not form a circular shadow.

- A solar eclipse occurs when the moon comes between the sun and the earth, aligning in a straight line.
- This alignment causes the moon to cast a shadow on the earth.
- The shadow forms because the moon blocks the sunlight from reaching certain parts of the earth.
- The dark inner part of the shadow, where the sun is completely obscured, is called the umbra, and the outer part, where the sun is partially seen, is the penumbra.
- Thus, the correct answer is B: Formation of a shadow of the moon on the earth.

- In a completely dark room, there is no source of light.
- Mirrors reflect light to form images, but without any light, reflection cannot occur.
- Since visibility requires light to enter the eyes, and the mirror needs light to reflect an image back to you, no image will be seen in total darkness.
- Therefore, in complete darkness, holding a mirror in front of you will result in seeing nothing, leading to the correct answer: D: No image.

- Sanchit's experiment shows that light travels in a straight line by using a flashlight and a cardboard with a small hole.
- The light passing through the hole forms a narrow, straight beam, illustrating that light doesn't bend around obstacles.
- This behavior of light is known as the rectilinear propagation of light.
- Both statements A and B are correct and describe the same phenomenon.
- Therefore, the conclusion is option C: "A and B both."

Butter paper is an example of a translucent object. Here's why:

• Translucent objects: These allow some light to pass through but scatter it, so objects on the other side are not clearly visible.


• Butter paper: It lets light pass through but diffuses it, making it difficult to see through clearly.


• This quality distinguishes it from:
  
  
  • Transparent objects: Allow all light to pass through clearly (e.g., clear glass).
  
  
  • Opaque objects: Do not allow light to pass through (e.g., wood). 
  
   

Concave mirrors are spherical mirrors with the curved surface facing inwards. Concave mirrors used by dentists are called “Mouth Mirrors”. They provide a clear and magnified image of the tiniest of the things in the mouth and thus help the dentist identify the problem.

Lateral inversion is a phenomenon in which left appears to be right and vice versa. It is due to the direction that light follows when it strikes a reflecting surface, generally a mirror.

Shadows are formed when something comes into the path of light through which light rays couldn 't pass as light travels in straight line (or rectilinear propagation). It forms on the opposite side of the light source.

- Sanchit's Statement: Correct. Light is energy that enables us to see objects, but light itself is not visible.
- Ananya's Statement: Correct. A pin-hole camera produces an inverted image due to light rays crossing at the aperture.
- Ruhi's Statement: Incorrect. The moon is not luminous; it reflects sunlight, which makes it visible.
- Rohit's Statement: Correct. Periscopes use plane mirrors to reflect light, allowing observation over obstacles.

Thus, Ruhi's statement is incorrect because the moon reflects light rather than emitting it.

Correct option is A.  Both B and C are correct

1. The colour of shadow does not depend on the colour of the object. The shadow is always black in colour. So, all three towels will form same colour shadow.
2. The colour of shadow does not depend on the colour of the object, it depends on the thickness of the object. The shadow is always black in colour. So, all three towels will form same colour shadow

A pinhole camera is a simple camera without a lens but with a tiny aperture, a pinhole camera – effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect.