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The range of visual spectrum is
300nm - 1000nm. 300nm - 1000nm
480nm - 1000nm. 480nm - 1000nm
480nm - 760nm. 480nm - 760nm
300nm - 760nm. 300nm - 760nm
480nm - 760nm.
480nm - 760nm
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. In the context of illumination engineering, this range is typically considered to be between 400 nm (violet) and 760 nm (red).
The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. In the context of illumination engineering, this range is typically considered to be between 400 nm (violet) and 760 nm (red).
c=f╬╗ тАФ Relationship between speed of light (c), frequency (f), and wavelength (╬╗)
E=╬╗hcтАЛ тАФ Energy of a photon where h is Planck's constant
Human vision relies on photoreceptor cells called cones in the retina, which are sensitive to electromagnetic radiation within specific wavelength bands. When photons in the range of 400nm to 760nm strike the retina, they trigger neural signals interpreted by the brain as light and color. Outside this range (Ultraviolet below 400nm and Infrared above 760nm), the human eye lacks the necessary pigment-protein receptors to convert radiation into visual stimuli.
The visible spectrum is a small segment of the electromagnetic spectrum.
Wavelengths shorter than 400nm are classified as Ultraviolet (UV).
Wavelengths longer than 760nm are classified as Infrared (IR).
The sensitivity of the human eye varies across this range, peaking at approximately 555nm in daylight conditions.
Enables color perception in biological organisms.
Facilitates the design of artificial lighting systems based on eye sensitivity.
Limitations in sensing outside the range lead to invisible hazards (e.g., UV radiation).
Varies slightly between individuals and ages.
Illumination and Lighting Design
Optical sensor technology
Display technologies (LED/LCD)
While some scientific sources define the range strictly from 380nm or 400nm to 700nm or 760nm, 400nm-760nm is the standard accepted range in illumination and electrical engineering textbooks.
Option A and D are incorrect as 300nm falls within the Ultraviolet range, which is invisible to humans.
C is correct тАФ The standard range of the human visual spectrum used in illumination engineering is approximately 400nm to 760nm.
Remember that 555nm is the wavelength where human eyes are most sensitive; questions often ask for the peak sensitivity wavelength in illumination engineering.