Dispersion of Light and Colours Flashcards
What is the dispersion of white light by a triangular prism?
Dispersion is the splitting of white light into its constituent colors (spectrum) when it passes through a triangular prism. This occurs because different colors of light have different refractive indices and thus bend by different amounts.
How is a pure spectrum produced?
A pure spectrum is produced by passing white light through a narrow slit and then through a prism or diffraction grating, separating the light into distinct colors without overlap.
What is color mixing by addition and subtraction?
Color Addition: Combining primary colors of light (red, green, and blue) to produce secondary colors (cyan, magenta, and yellow) and white light.
Color Subtraction: Removing colors from white light using filters or pigments, which absorb certain wavelengths and reflect others, creating various colors.
How do color filters work?
Color filters work by allowing only certain wavelengths of light to pass through while absorbing the others. For example, a red filter allows red light to pass through and absorbs other colors.
How is a rainbow formed?
A rainbow is formed by the refraction, dispersion, and reflection of sunlight in water droplets in the atmosphere. Light enters a droplet, disperses into its component colors, reflects off the back of the droplet, and then refracts again as it exits, forming a circular arc of colors.
What is the electromagnetic spectrum?
The electromagnetic spectrum is the range of all types of electromagnetic radiation, from low-energy radio waves to high-energy gamma rays. It includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
How do objects get their colors?
Objects have colors based on the wavelengths of light they reflect. An object appears red, for instance, because it reflects red light and absorbs other colors.
What are the sources and uses of various types of radiation in the electromagnetic spectrum?
- Radio Waves: Produced by oscillating charges, used in communication (e.g., radio, TV).
- Microwaves: Produced by electronic devices, used in cooking and communication.
- Infrared: Emitted by warm objects, used in night-vision cameras and remote controls.
- Visible Light: Produced by the sun and artificial sources, used for vision and illumination.
- Ultraviolet: Emitted by the sun, used in sterilization and detecting counterfeit money.
- X-rays: Produced by high-energy collisions, used in medical imaging.
- Gamma Rays: Emitted by radioactive substances, used in cancer treatment and sterilizing medical equipment.
