Differentiate between the structure and function of incandescent bulbs and LED lamps.
Explanation of a fused bulb.
Anatomy of an incandescent torch bulb.
Many older torchlights use a small incandescent lamp to produce light. If you look closely inside the glass bulb, you will see a very thin wire in the middle.
This thin glowing wire is called the filament. When electricity passes through it, the filament gets extremely hot and glows brightly to produce light.
Diagram of an incandescent bulb with filament and terminals labeled.
The two terminals of an incandescent lamp are the metal case and the metal tip at the base.
Fill-blank on incandescent bulb parts.
In an incandescent lamp, the thin wire inside the glass bulb that gets hot and glows is called the . This wire is supported by two thicker wires that connect to the metal and the metal at the base. These connection points form the two of the lamp and are fixed so they do not touch each other. In contrast, a Light Emitting Diode, or , does not use a glowing wire to produce light. It has two attached wires of unequal length, where the longer wire is the terminal. The shorter wire must be connected to the terminal of the battery. Current can pass through this modern lamp in only one , so it must be connected correctly to glow.
Structure and polarity of an LED.
Many torches used today have a Light Emitting Diode (LED) instead of a traditional incandescent lamp. The biggest difference? LEDs do not have filaments inside them.
Because they lack a delicate filament, LEDs are often more durable and energy-efficient than older bulbs.
Visual showing LED legs and their polarity.
LEDs have directional legs (+/-) and do not contain breakable filaments.
Matching exercise comparing the two lamp types.
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