Identify a diode, an LED, a resistor and a capacitor

Identify a diode, an LED, a resistor and a capacitor

Aim

To identify a diode, an LED, a resistor and a capacitor from a mixed collection of such items.

Apparatus and Material Required

Multimeter, a collection of diode, LED, resistor and capacitor.

Principle

1. A diode is a two terminal device. It conducts when forward biased and does not conduct when reverse biased. It does not emit light while conducting.
2. A LED (light emitting diode) is also a two terminal device. It conducts when forward biased and does not conduct when reverse biased. It emits light while conducting.
3. A resistor is a two terminal device. It conducts equally in both directions.
4. A capacitor is a two terminal device. It does not conduct but stores some charge when dc voltage is applied.

Procedure

1. Look for colour bands, if it has a typical set of three colour bands followed by a silver or gold band, the component is a resistor.
2. Connect the multimeter terminals (in resistance mode-highest range) to the component terminals and watch for multimeter deflection. Also repeat by reversing the component terminals.
3. If the multimeter shows an equal deflection in both the directions, the component is a resistor.
4. If the deflection is accompanied with emission of light, in one direction and a much less or zero deflection in the other direction the component is a LED.
5. If the multimeter does not show any deflection in one direction and shows deflection with no light emission in the other direction then, the component is a diode.
6. If the multimeter does not show any deflection on connecting its terminals either way to the component, it is a capacitor. But if capacitance of capacitor is large, multimeter may show a momentary deflection.

Results

A diode, a LED, a resistor and a capacitor are identified respectively from a mixed collection.

Conclusion

Through this experiment, we successfully identified the given electronic components—diode, LED, resistor, and capacitor—by analyzing their physical appearance, color codes, and electrical characteristics using a multimeter.

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Reference: NCERT Lab Manual

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