GK SCIENTIST

General Knowledge One Stop Source
Menu
  • Home
  • Social Science
    • History
    • Political Science
    • Geography
  • Science
    • Physics
    • Chemistry
    • Biology
  • Chemistry Notes
  • Mathematics
  • Computer
  • Tutorial MySQL
  • Tutorial Python
  • Java Tutorial
  • English Grammar
  • English Essay
  • Indian Anthropology
  • Philosophy
  • Solved Paper
  • UPSC
  • Current Content
    • Current Affairs
    • RSTV News
    • Yojana and Kurukshetra Gist
  • Donate
  • Contact Us

If you are interested in advertising to our audience, submit the advertising enquiry form.

Advertising Enquiry
Science

Sources of Light

Gk Scientist April 16, 2021 No Comments
Tweet WhatsApp Telegram

Table of Contents

  • Sources of Light:
    • Natural Sources of Light:
    • Artificial Sources of Light:
  • Why are some light sources hot and others cold?

Sources of Light:

Light is defined as a form of energy which when falls on the objects, enables us to see them. Light is one of the most important forms of energy. Without light, life on earth would not exist. The branch of physics, which deals with the phenomena accompanying light and vision is called optics. Important sources of light are the following-

Natural Sources of Light:

Sun is the main and brightest natural source of light. It illuminates all the planets, their satellites and other celestial bodies. Stars are also natural sources of light. Being very far away, they are not able to give sufficient light to the earth.

Another example of a natural source of light is the firefly (jugnu). It is a glowing insect. It gives very feeble light. There are certain kinds of fish too which give out light.

Artificial Sources of Light:

These are man-made sources of light. Some of the examples are candles, lanterns, gas lamps, electric bulbs and fluorescent tubes. Bodies are visible only by the light they send to our eyes and thus act as sources of light. They may be either luminous or non-luminous.

  • Luminous Sources- Luminous sources of light are defined as those sources of light which give out light of their own. Examples are sun, lamp, candle, electric bulb etc.
  • Non-Luminous Sources- These sources do not emit light of their own but reflect the light falling on them and hence become visible. The moon is not a luminous object because the moon does not produce any light of its own. It reflects the sun’s light. It acts as a cold non-luminous mirror. All the planets and moon are reflectors of light. Earth also reflects the light of the sun. The light of the sun reflected from the surface of the earth is called the earth light.

Why are some light sources hot and others cold?

Many light sources often give out heat as well. The sun gives both heat and light. A firefly gives out only light and no heat.

All solids, liquids and gases emit light when they are heated to a high temperature. The electric bulb has a wire inside, called the filament. When this filament is heated by passing an electric current through it, it gives out light. Fluorescent lights are columns of gas heated by electrical energy. In the flame of a candle, the light is given out by hot particles of carbon, heated to incandesce. The term used to describe a glowing hot object is incandesce.

Different mechanisms are responsible for the emission of light from different sources. A hot filament that glows in an electric bulb is said to be incandescent. It is a hot source of light. Here, heat is responsible for the emission of light. The burning of a candle or a match stick is another example of incandescence. A tube light is not incandescent because it does not use a filament. It is a cold source of light. A firefly gives out light but no heat, due to some chemical reactions taking place within its body. The firefly is also a cold source of light. The energy of some chemical reactions called nuclear reactions within the sun and stars is released both as heat and light.

Tubelight or fluorescent light is often called ‘cool’ light because it gives out little heat and much light. The filament of an electric bulb has a temperature of about 2000°C.


Optical FibreWhy the Stars do not Collapse?
Molecular Theory of MagnetizationSpeed and Velocity
Physical Properties of Pure WaterScalars and Vectors
Sources of EnergyProperties of Fluids– NIOS
Prev Article
Next Article

Related Articles

Plasmolysis and Deplasmolysis
What are Plasmolysis and Deplasmolysis? Plasmolysis- When a plant cell …
Gk Scientist April 27, 2021 Science

Plasmolysis and Deplasmolysis

What is vernalization in plants?
Vernalization in plants: It is defined as the low-temperature treatment …
Gk Scientist October 4, 2020 Science

What is vernalization in plants?

EMF Of Galvanic Cell
EMF Of Galvanic Cell: In a Galvanic Cell, the electrons …
Gk Scientist May 11, 2021 Science

EMF Of Galvanic Cell

Group 2 Elements (Alkaline Earth Metals)
Alkaline Earth Metals: The elements Beryllium (Be), Magnesium (Mg), Calcium …
Gk Scientist February 17, 2021 Science

Group 2 Elements (Alkaline Earth Metals)

Proteins- Simple and Conjugated proteins
What are the proteins? Proteins are the linear, unbranched polymers …
Gk Scientist March 1, 2021 Science

Proteins- Simple and Conjugated proteins

Physical Properties of Pure Water
Physical Properties of Pure Water: (a) Nature- Pure water is …
Gk Scientist February 4, 2021 Science

Physical Properties of Pure Water

Noise Pollution- Sources, Effects and Control Measures
Noise Pollution: Noise Pollution is a direct result of technological …
Gk Scientist April 17, 2021 Science

Noise Pollution- Sources, Effects and Control Measures

Kirchhoff’s Laws
Kirchhoff’s Laws: There are two laws as follows- Kirchhoff’s 1st …
Gk Scientist October 29, 2021 Science

Kirchhoff’s Laws

Leave a Reply Cancel Reply

Search

  • Popular
  • Recent




GK SCIENTIST

General Knowledge One Stop Source

Information

  • About Us
  • Terms and Condition, Disclaimer
  • Contact Us

Android Apps

  • IAS App For English Medium Students
  • IAS Basics App For English Medium Students
  • IAS Hindi App For Hindi Medium Students
DMCA.com Protection Status

Popular Tags

Biology (33) Biology Questions (88) Chemistry (57) Computer (215) Current Affairs (4) Current Content (0) Economy (16) English Essay (172) English Grammar (75) English Literature (10) Geography (83) History (259) Indian Anthropology (11) Indian Polity (14) JKAS Mains Question Papers (17) Mathematics (68) Moral Science (7) NCERT & Other Boards Books (25) Philosophy (114) Physics (89) Political Science (132) RS TV News (33) Science (553) Social Anthropology (7) Social Science (17) Solved Paper (47) UPSC (7) UPSC Mains Question Papers (26)

Downloads

  • NCERT Books
  • Old NCERT Books
  • NIOS Books For IAS, SSC, and State PSC Exam
  • Tamil Nadu Board Books: Important For UPSC, SSC, and State PSC Exam
  • Modern Indian and World History Notes For IAS Exam
  • UPSC Topper 2013 Gaurav Agrawal Notes For IAS Preparation
  • UPSC IAS Prelims General Studies – Previous Year Papers
  • UPSC Mains Question Papers

Copyright © 2023 GK SCIENTIST
Theme by MyThemeShop.com& Hosted On Cloudways

Ad Blocker Detected

Our website is made possible by displaying online advertisements to our visitors. Please consider supporting us by disabling your ad blocker.

Refresh