Q20 Read the passage given below and answer the questions that follow.
A rain sensor is a device used for sensing rain. They are used to automatically activate windscreen wipers to remove water from the windshields An IR LED is used to shine infrared light onto the windshield at an angle of 45°, which is then detected using an IR photodiode.
(i) Name the two semiconductor diodes used in the rain sensor. (ii) What kind of biasing is used in each of these diodes? (iii) Draw the symbol of LED. Useful Constants & Relations:
