Meeta father was driving her to the school. At the traffice signal she noticed that each traffic light was made of many tiny lights instead of a signal bulb. When Meeta asked this question to her father's he explained the reason for this.
Answer the following question 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 light in traffice signal called and how do these operate?

Explanation

(i) She is curious and have a quest for knowledge. Meeta's father is very helpful and aware of scientific facts.
(ii) He said that these are LED bulbs and their power consumption is very low.
(iii) Light emiting diode (LED) is a heavily doped forward biased p-n junction. The order of minimum band gap of an LED to emit light in the visible range is about 1.8 ev.