How many polarized filters are needed minimally to block light intensity?
A) one filter
B) three filters perpendicular to each other
C) two filters parallel to each other
D) two filters perpendicular to each other
Consider the following properties. Which applies to light?
A: mechanical wave
B: electromagnetic wave
C: travels in circular paths
D: travels in a straight line
A) a, b, and d
B) b and d
C) a, b, and c
D) a and c
To answer the first question about the number of polarized filters needed to block light intensity, the correct answer is D) two filters perpendicular to each other.
To understand why, let's briefly explain the concept of polarization. Light waves are composed of electric and magnetic fields that oscillate in various directions. When light is unpolarized, the electric and magnetic fields vibrate in random orientations. However, by passing light through a polarizing filter, the waves can be aligned to vibrate in a single plane, which is known as polarization.
When two polarizing filters are placed parallel to each other, the intensity of light passing through them remains relatively unchanged because both filters allow similar orientations of polarized light to pass through. In contrast, when two polarizing filters are placed perpendicular to each other, only a minimal amount of light is transmitted. This is because the second filter blocks the light waves that have been already polarized by the first filter, resulting in a significant reduction in transmitted light intensity.
Moving on to the second question, the correct answer is B) b and d.
Light is classified as an electromagnetic wave (B) because it consists of oscillating electric and magnetic fields. Additionally, light travels in a straight line (D) unless it encounters an obstacle or is refracted or reflected by a medium. While certain phenomena may cause light to exhibit circular paths (C), such as when it passes through a curved medium or interacts with certain objects, this is not a universal property of light. As for mechanical waves (A), those are waves that require a medium, such as air or water, to propagate, and since light can travel in a vacuum, it is not considered a mechanical wave.