1. There are two symbols for NMOS, one with outward arrow & other with inward. I read that it represent PN junction. I don't get it how.

http://en.wikipedia.org/wiki/File:Mosfet_N-Ch_Sedra.svg
http://en.wikipedia.org/wiki/File:IGFET_N-Ch_Enh_Labelled.svg

2. In saturation region in mosfet, channel gets pinched off. But if it gets pinched off, how current flows through i?

3. Any examlpe ckt showing mosfet in saturation region.

4. What's body effect in fes

 

There are different kinds of FETs.

Some FETs are normally on and will turn off with a signal applied to their gate.
Other FETs are normally off and need a signal to turn on.

You can find out more with some research.

Sorry but I need to head out now.

 

http://www.allaboutcircuits.com/vol_3/index.htmlHere in AAC we have a very good e-book for beginners, which explain all of your questions.
http://www.allaboutcircuits.com/vol_3/index.html

Good Luck

 

HI,
I have checked the link, but it showed "pending" message for fets.

 

Read these
http://www.allaboutcircuits.com/vol_3/chpt_2/10.html
http://www.allaboutcircuits.com/vol_3/chpt_6/2.html

I know Enhancement-type IGFETs is pending but after reading Depletion-type IGFETs you will get some idea about Enhancement-type IGFETs.Later you can search more on Enhancement-type IGFETs on internet.

Good Luck