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Electronics
Junior Cert Electronics
Term | Definition |
---|---|
Diode | Allows Electricity to flow in one direction only ("PN" turns into symbol) Can be used to convert a.c. to d.c. |
LED | Light Emitting Diode It gives out light when a current passes through it. |
LDR | Light Dependant Resistor It is used to turn on and off street lights |
Forward Bias | "P" terminal connected to the Positive end and "N" Terminal to the negative end |
Negative Bias | "P" terminal connected to the Negative end and "N" Terminal to the Positive end |
Everyday Applications of an LED | Used in mobile phones, computers, display boards, |
Everyday Applications of a Diode | In electrical circuits can be used to make sure electricity flows only in one direction. Can be used to convert a.c. to d.c. |
Everyday Applications of a LDR | Used in cameras to control the settings while taking photos in bright and dark light situations |
How do you measure the resistance of an LDR under varying degrees of brightness of Light? | Connect up an Ohmmeter, dimmer switch and lamp and measure the resistance under different levels of brightness. |
How does the resistance in an LDR vary with Light levels? | The value of the resistance increases as the brightness of the Light is decreased |
What electronic device is always used with an LED? | Needs a resistor in series with it. |
How is the device which is always used with the LED attached in a circuit? | Always in Series |