I have been trying to understand the operation of transistors for a while now. Today I thought to put what I learnt into test. Cutoff operation of a NPN transistor. As I read in one of the transistor tutorials in Sparkfun, in order to push transistor to Cut off state Vb < Vc and Vb < Ve. So here goes my test circuit to understand the cut off operation better and the voltage readings I got when measured using a Multimeter.
In the above I got few questions
- Why there is negative voltage of -0.34v exhibited across LED? ( its green LED rated 2v / 20mA and I measured with Positive probe in Anode and Negative in Cathode )
- I have read there exist leakage current even when the transistor is in Cut off state, what exactly is the source of this leakage current? Does it originate from Collector and flows to emitter?
- If there is a leakage current why there is no voltage drop across the resistor R2?
- Are there any other current flow in this circuit except for the leakage current?
Kindly help me in understanding this. Any leads or links where I can find answers will be highly appreciated.