LED - Prior Knowledge

Which one of the following properties makes an LED different from a regular diode?

• LEDs can handle higher voltages

• LEDs emit light when forward biased

• LEDs have no polarity

• LEDs work only with AC current

Which one of the following statements is true about an LED?

• It allows current to flow in both directions

• It is not a polarised component

• It only allows current to flow in one direction

• It emits light when reversed biased

Which one of the following conditions is necessary for an LED to emit light?

• The LED must be reversed biased

• The LED must be forward biased

• The LED must be connected in parallel

• The LED must be connected to an AC source

Select the correct circuit symbol for an LED

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State two ways of finding the polarity of an LED

• Checking the colour of the LED

• By looking at the length of the legs

• By connecting it directly to a 9V battery

• By finding the flat side of the LED