Question

how can light be seen through all the index card?​

Answer 1

Explanation:

For more on light see Light Science for Kids. For each index card, use a ruler to draw lines connecting opposite corners of the card. At the intersection of the two lines, use a hole puncher to punch a hole in the center of the index cards. ... Arrange the index cards so that light can be seen through all the holes.

Answer 2

Answer:

Light can be seen through all the index cards because:

The holes are in alignment and the light travels in straight line path.