Question

What is light ......?
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Answer 1

Answer:

Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometers, or 4.00 × 10⁻⁷ to 7.00 × 10⁻⁷ m, between the infrared and the ultraviolet.

Frequency

The frequency is the number of waves that pass a point in space during any time interval, usually one second. We measure it in units of cycles (waves) per second, or hertz. The frequency of visible light is referred to as color, and ranges from 430 trillion hertz, seen as red, to 750 trillion hertz, seen as violet.

Particles

The light particle conceived by Einstein is called a photon. The main point of his light quantum theory is the idea that light's energy is related to its oscillation frequency (known as frequency in the case of radio waves). ... Photons have energy equal to their oscillation frequency times Planck's constant.

Equation

Formula: c = f where: c = the speed of light = 300,000 km/s or 3.0 x 108 m/s. = the wavelength of light, usually measured in meters or Ångströms (1 Å = 10-10 m) f = the frequency at which light waves pass by, measured in units of per seconds (1/s).

Measurements

One candela per steradian is termed a lumen, which is the measure of light intensity people are most familiar with. However, what matters most in terms of measuring light intensity is the number of lumens falling on a surface, which is expressed as lux.

Answer 2

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Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nm, or 4.00 × 10⁻⁷ to 7.00 × 10⁻⁷ m, between the infrared and the ultraviolet.