11.5 Reading Quiz - Polarization
Polarization is the process of transforming unpolarized light into a light that is polarized. The polarization influences the cut-off wavelengths of filters, affects the focus of laser beams and can be of great importance when preventing unwanted back reflections. Test your understanding of polarization through the test below. Good luck.
- 1.
What is polarized light?
- A.
Where wave oscillates in one direction
- B.
Where wave oscillates in one plane
- C.
Where electric field component oscillates in one plane
- D.
Where magnetic field component oscillates in one plane
Correct Answer
C. Where electric field component oscillates in one planeExplanation
Polarized light refers to light waves where the electric field component oscillates in one plane. In unpolarized light, the electric field vibrates in all possible planes perpendicular to the direction of propagation. However, when light is polarized, the electric field oscillates in a specific plane, allowing for unique properties and applications. Polarized light is commonly used in various fields such as photography, 3D technology, and scientific research.Rate this question:
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- 2.
What happens when two polarizing filters are placed so that their axes of polarization are perpendicular to each other?
- A.
Transmitted light is slightly weaker
- B.
There is no transmitted light
- C.
Transmitted light is polarized
- D.
Transmitted light oscillates in all directions
Correct Answer
B. There is no transmitted lightExplanation
When two polarizing filters are placed with their axes of polarization perpendicular to each other, no transmitted light can pass through. This is because the filters are oriented in a way that blocks the passage of light waves that are not aligned with their respective axes. As a result, no light is able to pass through the filters, leading to the absence of transmitted light.Rate this question:
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- 3.
Brewster's Angle is when
- A.
Reflected light is completely plane polarized
- B.
Reflected light is partially polarized
- C.
No light is reflected
- D.
Angle between incident and reflected light is 90 degrees
Correct Answer
A. Reflected light is completely plane polarizedExplanation
Brewster's Angle is the angle at which the reflected light from a medium is completely plane polarized. This means that the reflected light waves vibrate in a single plane, perpendicular to the plane of incidence. At this angle, there is no partially polarized or unpolarized light. The angle between the incident and reflected light is not necessarily 90 degrees, as it can vary depending on the refractive indices of the two media.Rate this question:
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- 4.
What is the condition for Brewster's Angle?
- A.
90 degrees between incident and reflected rays
- B.
90 degrees between incident and refracted rays
- C.
90 degrees between reflected and refracted rays
Correct Answer
C. 90 degrees between reflected and refracted raysExplanation
The condition for Brewster's Angle is that there should be a 90-degree angle between the reflected and refracted rays. This angle occurs when light is incident on a surface at a specific angle known as the Brewster's Angle. At this angle, the reflected light becomes completely polarized, meaning it vibrates in a single plane. This phenomenon is used in various applications such as polarized sunglasses and anti-glare coatings.Rate this question:
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- 5.
If X is the intensity of unpolarized incident light on a polarizer, what is the intensity of the ray transmitted by the polarizer?
- A.
X/2
- B.
X cos ((angle)
- C.
X
- D.
X/sqrt(2)
Correct Answer
A. X/2Explanation
The intensity of the ray transmitted by the polarizer is X/2. A polarizer only allows light waves that are vibrating in a specific direction to pass through, blocking the waves that are vibrating perpendicular to that direction. In the case of unpolarized light, the waves are vibrating in all directions randomly. When this light passes through a polarizer, half of the waves that are vibrating in the correct direction are transmitted, resulting in an intensity of X/2.Rate this question:
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- 6.
To analyse an optically active substance, it must be placed
- A.
Before the polarizer
- B.
After the analyser
- C.
Between the polarizer and analyser
- D.
Doesn't matter as long as all three are in line.
Correct Answer
C. Between the polarizer and analyserExplanation
An optically active substance must be placed between the polarizer and analyzer in order to analyze it. This is because the polarizer polarizes the light before it passes through the substance, and the analyzer analyzes the changes in polarization caused by the substance. Placing the substance between the polarizer and analyzer allows for accurate analysis of the substance's optical activity.Rate this question:
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- 7.
An optically active substance...
- A.
Polarises light in vertical plane
- B.
Polarizes light in horizontal plane
- C.
Rotates plane of polarization
- D.
Reduces the degree of polarization
Correct Answer
C. Rotates plane of polarizationExplanation
An optically active substance is capable of rotating the plane of polarization of light. When unpolarized light passes through such a substance, the plane of polarization of the light is rotated as it travels through the material. This phenomenon is known as optical rotation and is caused by the interaction between the light and the asymmetric molecular structure of the substance. The amount of rotation depends on factors such as the concentration of the substance and the length of the path the light travels through it.Rate this question:
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- 8.
2 polarizing filters are placed at 30 degrees to each other. Unpolarized light of intensity X is inident on the polarizer. What is the intensity of transmitted light after the second polarizer?
- A.
X
- B.
X/2
- C.
X/sqrt(2)
- D.
X/4
Correct Answer
D. X/4Explanation
When unpolarized light passes through a polarizing filter, it becomes polarized in a single plane. When a second polarizing filter is placed at a 30-degree angle to the first one, only a component of the polarized light aligned with the second filter's axis is transmitted. The intensity of the transmitted light is given by Malus' Law, which states that the intensity is proportional to the square of the cosine of the angle between the polarization axes. In this case, the angle is 30 degrees, so the intensity of the transmitted light is (cos(30))^2 = (sqrt(3)/2)^2 = 3/4 = X/4.Rate this question:
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- 9.
A 1 molar solution of 20cm depth of sugar solution rotates angle of polarization by 10 degrees. Through what angle does 40cm of 2M solution rotate the plane of polarization
- A.
5 degrees
- B.
10 degrees
- C.
40 degrees
- D.
80 degrees
Correct Answer
C. 40 degreesExplanation
The angle of rotation is directly proportional to the concentration and the path length of the solution. In this case, the concentration of the 2M solution is twice that of the 1M solution. Therefore, the angle of rotation for the 40cm depth of the 2M solution would be double the angle of rotation for the 20cm depth of the 1M solution. Since the 1M solution rotates the angle of polarization by 10 degrees, the 2M solution would rotate it by 20 degrees. Therefore, the correct answer is 40 degrees.Rate this question:
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- 10.
When an LCD is swtiched on, the liquid crystal rotates the angle by how many degrees?
- A.
0
- B.
45
- C.
90
- D.
180
Correct Answer
A. 0Explanation
When an LCD is switched on, the liquid crystal does not rotate the angle at all. This is because the liquid crystal molecules are aligned in a specific direction and when an electric field is applied to them, they do not rotate. Therefore, the angle of rotation is 0 degrees.Rate this question:
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- 11.
Are there any areas of this section that you do not understand very well, and you would like to be reviewed?
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Current Version
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Mar 20, 2023Quiz Edited by
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Oct 18, 2012Quiz Created by
Gboulton
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