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Question : 23
Total: 26
SECTION -D
Meeta's 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's father give?
(iii) What are the tiny lights in traffic signals called and how do these operate?
Solution:
Answers of part (i) ,(ii), (iii)
(i) Values displayed by Meeta:
Inquisitive / Keen Observer / Scientific temperament / (Any other value.) Values displayed by Father :
Encouraging/Supportive/ (Any other value)
(ii) Meeta's father explained that the traffic light is made up of tiny bulbs called light emitting diodes (LED)
(Also accept other relevant answers)
(iii) Light emitting diode :
These diodes (LED's) operate under forward bias, due to which the majority charge carriers are sent from these majority zones to minority zones. Hence recombination occur near the junction boundary, which releases energy in the form of photons of light.
(i) Values displayed by Meeta:
Inquisitive / Keen Observer / Scientific temperament / (Any other value.) Values displayed by Father :
Encouraging/Supportive/ (Any other value)
(ii) Meeta's father explained that the traffic light is made up of tiny bulbs called light emitting diodes (LED)
(Also accept other relevant answers)
(iii) Light emitting diode :
These diodes (LED's) operate under forward bias, due to which the majority charge carriers are sent from these majority zones to minority zones. Hence recombination occur near the junction boundary, which releases energy in the form of photons of light.
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