Charge on three metallic plates

[zorro]

why are you making such an easy question so complicated...

the capacitor made of the 1st plate and left side of middle plate has no field outside it ... so i won't have any force on the charge on the right side of middle plate and and third plate

Yeah I got it now. The field on the right side of the middle plate gets canceled due to the first plate and the left side of the middle plate. I was very much confused and surprised after reading post #16. I figured out that its wrong.

Yup. http://en.wikipedia.org/wiki/Electrostatic_induction" .

That is NOT polarisation of metals
Polarisation is the characteristic property of those materials which don't have free electrons. Metals have free electrons and they get induced.

 

[gneill]

That is NOT polarisation of metals
Polarisation is the characteristic property of those materials which don't have free electrons. Metals have free electrons and they get induced.

Sorry, but when there is a separation of opposite charges in an object, the object can be said to be polarized --- it has a "+" end and a "-" end. Whether or not the separation occurs due to induction or by some other method of sequestering or implanting the charges is irrelevant.

 

[zorro]

Literally it may mean separation of charges. But I did not see anyone (except you offcourse ) to use that term for metals in physics.
It's used specifically for dielectrics. Read this http://en.wikipedia.org/wiki/Polarization_density