Graded MDB will be opened on Friday 20th February 2015 at 12:00am. This discussion board will be closed on 21th February 2015 at 11:59pm.GDB will remain open for 48 hours. It is important for every student to take part in this discussion board. Your comments will be graded, which is worth 5% of your total marks.
The topic is:
"Electrical components, Diode, Transistors are frequently used in electronic devices. By what materials these components are manufactured? Describe the reasons/ characteristic of these materials"
Instructions about GDB are given below
- Your answer should be concise and not exceed more than 150 words.
- Don’t put duel entries, Post your answer only once.
- Any one who copy and paste the comments of others will be graded zero marks.
- No answer will be accepted through email after closing of GDB.
Please, inform all the students to take part in this discussion, other wise they will miss marks.
These materials are prepared from semiconductors which are in the 4th group of the periodic table. Then doping is done from members of fifth group to make it n type and from members of 3rd group to make it p type. Now electrons can flow from n type side towards the p type side and not the inverse. …. . . . .
ReplyDeleteThe reason for making them from semiconductors is that we don’t want to flow the current freely like metals as we can not control direction of current in the with doping of p and n type material. …… . .. ..
Basic characteristic of these materials is that they allow the current to pass only to the limited extent. They behave almost like insulator in pure form as they don’t have free electrons in the outer shell but when doped with fifth group elements, they allow the current to pass to some extent . When p-type semiconductor is adjacent to n type then electron of p type can fall in hole of p type and current can flow..