What is an Arc Lamp? – Working Principle, Advantages, and Applications

What is an Arc Lamp?

An Arc Lamp is a type of electric lamp that produces light by creating an electric arc in the gap between two electrodes when the electric supply is connected to these electrodes. The first arc lamp was invented by Sir Humphry Davy in 1807.

Working Principle of Arc Lamp

In an arc lamp, two electrodes touching each other are connected to a source of electricity so that an electric current flows through the electrodes, as shown in Figure-1.

Now, if the two electrodes are separated a bit from each other, even then they carry an electric current and in the gap between the electrodes an electric arc is created as shown in Figure-2.

This electric arc has tremendous heat and temperature and light is produced from the lamp.

Types of Arc Lamps

Based on the above discussed principle, different types of arc lamps are designed. These arc lamps are −

  • Carbon Arc Lamp

  • Flame Arc Lamp

  • Magnetic Arc Lamp

Advantages of Arc Lamp

Some of the major benefits of using Arc lamps are as follows −

  • Arc lamps produce bright light.

  • Arc lamps can illuminate a large surface area such as a large length of streets, large factories, etc.

  • Arc lamps are cheaper than other street lamps, oil lamps, and gas discharge lamps.

Disadvantages of Arc Lamps

The disadvantages of using arc lamps are listed below −

  • The arc lamps will damage when the sparks or excessive heat be generated.

  • The electrodes of an arc lamp need to be replaced after short period of time. Thus, this adds an extra cost and time.

  • When the arc lamps burn, they generate flickering and buzzing sound.

  • Arc lamps also generate dangerous rays like UV rays that may impact human health.

Applications of Arc Lamps

Arc lamps are used in −

  • Cinema projectors

  • Search lights

  • Camera flashlights

  • Therapeutics

  • Microscope lighting

  • Motion pictures

  • Follow spots

  • Endoscopic instruments

  • Flood lights

  • Blue printing, etc.