Learnabout Electronics

- Opto Coupled Devices

Module 5.5

Optocoupler Quiz

Try this quiz based on optocouplers. Hopefully it'll be easy. Submit your answers but don't be disappointed if you get answers wrong. All the information you need is on this website. Find the right answer and learn about transistors as you go.


Optocoupler question 1
What type of optocoupler output is illustrated Fig. 5.5.1?


A phototransistor produces more current than a photodiode because - (Choose an answer to complete this sentence)


Which of the following operation modes do photo proximity detectors normally use?


Optocoupler question 4
Fig. 5.5.2 illustrates an IL300 audio optocoupler, which uses one infrared LED and two photodiodes. What is the usual purpose of the second photodiode?


An optocoupler having a maximum input current (IF) of 50mA is chosen to be driven by a current of 20mA. Which of the following answers would be a valid reason for this?


Optocoupler question 6
Which of the formulae in Fig.5.5.3 correctly describes the CTR of an optocoupler?


Optocoupler question 7
What is the purpose of RV1 in the audio optocoupler circuit shown in Fig 5.5.4?


Optocoupler question 8
Refer to Fig. 5.5.5. What will be the approximate voltages at the collector of the 2N3904 transistor when the LED is 'On' and 'Off'?


Compared to a photo-diode, which of the listed advantages and disadvantages would be expected of a photo-transistor


Optocoupler question 10
Refer to Fig. 5.5.6. With the input and output signals shown, what level of signal voltage would you expect at point A?

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