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LED
An LED (Light-Emitting Diode) emits light when forward current flows. It is polarized and usually needs a series resistor to limit current.
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LED
An LED is a tiny electronic light made from semiconductor material.
Current must pass through it in the correct direction.
Recommended for Class 10
LED
LED stands for Light-Emitting Diode.
An LED is a semiconductor diode that emits light when a suitable forward current passes through it.
Like an ordinary diode, an LED is polarized, meaning its direction of connection matters.
Energy Conversion
An LED converts electrical energy mainly into light, although some energy is also transferred as heat.
Why a Resistor Is Often Used
An LED should not normally be connected directly to a source that can drive excessive current through it.
A suitable series resistor is commonly used to limit current.
Applications
LEDs are used in:
indicator lights; displays; lighting; traffic signals; * electronic equipment.
LED — Advanced
In an LED, electron-hole recombination releases energy in the form of photons. The emitted colour depends on the semiconductor material and its energy-band structure.
Common Mistakes
Common Mistakes
- Mistake
Mistake: LED means "Light Electrical Device." Correction: It means Light-Emitting Diode.
Revision Zone
60-Second Revision
Quick cues from this topic — use them for last-minute revision.
LED → Light-Emitting Diode.
Forward current → light.
Polarized → direction matters.
Series resistor → limits current.
- Definition
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Practice
PQ
Q1. Expand LED.
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Q2. Why is it polarized?
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Q3. Why use a series resistor?
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Q4. Give two applications.
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Q5. What energy conversion occurs?
Exam Practice
EQ
Q1. Define LED.
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Q2. Explain LED operation.
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Q3. Why is current limiting important?
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Q4. Give applications.
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Q5. Differentiate LED and ordinary diode in terms of purpose.
School-standard facts for Matric and Intermediate. Original explanations — not copied from textbooks.