Hi, I don't get how to do this at all because I missed the lesson so could someone please help me? I appreciate it a lot!(adsbygoogle = window.adsbygoogle || []).push({});

First problem:

http://img55.imageshack.us/img55/9403/physics8tl.jpg [Broken]

a) if the switch closes, what is i1? i1 is current at that position

b) graph v2 versus t graph

c) after a long time, if the switch opens, what is i2?

d) calculate Q (charge) of the capacitor

e) calculate U (potential energy) of the capacitor

Second problem:

There is a capacitor with two plates with very large surface area. They are set d distance apart and have equal but opposite charge densities.

a) diagram the current through the plates (no idea how to do this).

b) If a dielectric is added, does the electric potential increase, decrease, or stay the same? What mechanism causes this effect? (I think it goes down because of the q=cv formula but i dunno what mechanism).

Thanks a lot!

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# Two electricity problems

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