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!

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Two electricity problems

**Physics Forums | Science Articles, Homework Help, Discussion**