Question

Meeta'* father was driving her to the school. At the traffic signal she noticed that each traffic light was made of many tiny lights instead of a single bulb. When Meeta asked this question to her father, he explained the reason for this.

Answer the following questions based on above information :

(i) What were the values displayed by Meeta and her father ?

(ii) What answer did Meeta'* father give ?

(iii) What are the tiny lights in traffic signals called and how do these operate ?

Answer 1

(i) Values displayed by Meeta :

Inquisitive/Keen/Observer/Scientific temperament/Values displayed by father :

Encouraging/ Supportive/ (Any other value)

(ii) Meeta'* father explained that the traffic light - is made up of tiny bulbs called light emitting diodes (LED)

(iii) Light emitting diode

These diodes (LED', operates under forwards bias, due to which the majority charge carries are sent from these majority, zones,to *** zones. Hence recombination occur near the junction boundary, which releases energy in the form of photons of light.