1.
What is the least wavelength of ultraviolet wave?
Correct Answer
D. 10 nm
Explanation
The least wavelength of ultraviolet waves is 10 nm. Ultraviolet waves have shorter wavelengths than visible light, ranging from about 10 nm to 400 nm. The shorter the wavelength, the higher the energy of the wave. Therefore, 10 nm is the least wavelength of ultraviolet waves, indicating that it has the highest energy among the options given.
2.
Which of these is a source of ultraviolet wave?
Correct Answer
C. Sun
Explanation
The sun is a source of ultraviolet waves. Ultraviolet (UV) waves are a type of electromagnetic radiation with a wavelength shorter than that of visible light. The sun emits UV waves as part of its electromagnetic spectrum. These waves are responsible for causing sunburns, tanning, and can also have harmful effects on the skin and eyes if exposed for long periods without protection.
3.
Which of these is not an effect of ultraviolet wave?
Correct Answer
D. Cough
Explanation
Ultraviolet waves can cause sunburn and suntan because they penetrate the skin and damage the cells. However, ultraviolet waves do not have any direct effect on the respiratory system, so coughing is not an effect of ultraviolet waves.
4.
What does "ultra" means in Ultraviolet?
Correct Answer
C. Beyond
Explanation
The term "ultra" in Ultraviolet means "beyond" because the prefix "ultra-" is used to indicate something that is beyond or surpassing a certain limit or standard. In the case of Ultraviolet, it refers to a type of electromagnetic radiation that is beyond the violet end of the visible spectrum.
5.
What type of wave is ultraviolet?
Correct Answer
B. Electromagnetic wave
Explanation
Ultraviolet waves are a type of electromagnetic wave. Electromagnetic waves are characterized by their ability to travel through a vacuum, without the need for a medium. They consist of oscillating electric and magnetic fields that are perpendicular to each other and to the direction of wave propagation. Ultraviolet waves have a higher frequency and shorter wavelength than visible light, and they are typically produced by the sun and artificial sources such as UV lamps. They have various applications in fields like medicine, sterilization, and astronomy.
6.
Which of these is true about ultraviolet wave?
Correct Answer
C. It does not require a medium for propagation
Explanation
Ultraviolet waves do not require a medium for propagation. Unlike sound waves, which require a medium such as air, ultraviolet waves can travel through a vacuum, such as outer space. This is because ultraviolet waves are a form of electromagnetic radiation, which can travel through empty space.
7.
What percentage of ultraviolet ray is in sunlight?
Correct Answer
A. 10%
Explanation
Ultraviolet (UV) rays are a part of sunlight and are divided into three types: UVA, UVB, and UVC. Out of these, only a small portion of UVB rays is present in sunlight, which is responsible for causing sunburn and skin damage. Therefore, the correct answer is 10%, as it represents the approximate percentage of UVB rays in sunlight.
8.
Which of these is skin disease caused by ultraviolet radiation?
Correct Answer
C. pHotokeratitis
Explanation
Photokeratitis is a skin disease caused by ultraviolet radiation. It is a condition that affects the cornea, the transparent front part of the eye. Exposure to intense ultraviolet rays, such as those from the sun or tanning beds, can cause inflammation and damage to the cornea, leading to symptoms like pain, redness, tearing, and sensitivity to light. This condition is commonly referred to as "sunburn of the eye" and can be prevented by wearing protective eyewear and avoiding excessive exposure to UV radiation.
9.
Which of these is an application of ultraviolet wave?
Correct Answer
C. pHotograpHy
Explanation
Ultraviolet waves are used in photography to capture images that are not visible to the human eye. These waves have a shorter wavelength than visible light, allowing them to capture details and colors that are not normally seen. UV photography is commonly used in forensic investigations, art, and scientific research. It can reveal hidden patterns, textures, and fluorescence that are not visible under normal lighting conditions. By using UV filters and specialized equipment, photographers can create unique and striking images that showcase a different perspective of the world.
10.
Which of these produces ultraviolet ray?
Correct Answer
C. Electric arcs
Explanation
Electric arcs produce ultraviolet rays. When an electric current passes through a gas or vapor, it creates a high-intensity discharge of electricity known as an electric arc. This arc emits a wide range of electromagnetic radiation, including ultraviolet rays. Ultraviolet rays have a shorter wavelength than visible light and are invisible to the human eye. They are commonly used in various applications such as sterilization, fluorescent lighting, and tanning beds.