transistors working

[asif2001]

How does a transistor amplify a signal?
Why do we prefer NPN transistors over PNP transistors?

 

[dydt]

http://www.amasci.com/amateur/transis.html

check this site

dydt

 

[xnuke]

You claim &quot;Electrical&quot; as your area of expertise, yet you ask basic questions that every electrical engineer should be able to answer. I do not like the fact that you claim to have knowledge about a particular engineering area, yet obviously are an amateur.>:-<