Hint:Let us get some idea about light. Light, also known as visible light, is electromagnetic radiation that falls within the portion of the electromagnetic spectrum that the human eye can detect. Between the infrared and ultraviolet, visible light is classified as having wavelengths in the 400–700 nm range.
Complete answer: These are the following four man made sources of light: An electric bulb: An electric bulb is a type of light bulb that has a translucent or clear glass housing. It's often referred to as a light bulb. For more than a century, this simple system has been used to provide lighting. An electric bulb is a device that generates light when electricity is applied to it.
Candle: A candle is a flammable solid material, such as tallow, with an ignitable wick embedded in it that provides illumination and, in some cases, fragrance. A candle may also be used to provide heat or as a timekeeper.
An oil lamp: An oil lamp is a device that uses an oil-based fuel source to generate light continuously for a period of time. Oil lamps have been used for thousands of years and are still used today, though their use is less common in modern times.
A torch: A flashlight, also known as a torch in the United States or a torchlight in the United Kingdom, is a compact hand-held electric light. Previously, the light source was usually a miniature incandescent light bulb, but since the mid-2000s, light-emitting diodes (LEDs) have taken their place. Some flashlights may be used in flammable environments or underwater.
Note:All life on our planet is based on light. Plants use chlorophyll to synthesise nutrients from light and filter the air we breathe, demonstrating the value of light. Plants are important for the survival of both animals and humans.