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) Meet is curious and have a quality of learning. Meeta's father is a helping hand to her daughter and have good knowledge about the scientific facts.
(ii) Meeta's father told that these are LED bulbs and their power consuption is very low.
(iii) LED is a heavily doped p-n junction diode which under forward bias emit spontaneous radiation. The order of minimum band gap of an LED to emit light in the visible region is about 1.8eV.