Capacitors have polarity?

[lyberty5]

This morning I wired my TI regs for a new GCP, And when i turned on the 12V supply, two caps blew up, nothing dangerous but now I'm scared that it will happen again..

But I think I found the issue, I spent all year drawing caps as symetrical parrallel bars, it led me to think caps don't have polarity, but the cap itself is asymetrical, one leg is longer, and one side is blue..
I had previously wired a set of regs for my first gcp and nothing had happened but it was a year ago, I can't remember if I thought caps had polarity or not back then..

Anyways, to sum up, do caps have polarity? (do they have a + and -)

(apparently, wikipedia and my old blown up caps tend to say they do)

 

[superben51]

Electro caps do, ceramic don't. Long is positive short is negative.

 

[Mr. Hooker]

caps should have a stripe to indicate negative. not all will have marking in the stripe, but a stripe at the vary least.

 

[Hermaphroditus]

As they were saying, electrolytic capacitors definitely DO have a polarity. Those are the big black caps that you are used to seeing. Hooking them in backwards can lead to them blowing up, as you have seen. Ceramic capacitors, which are usually reddish-orange disks with leads, do not have a polarity.
In essence, when drawing circuit diagrams follow this:

 

[lyberty5]

That's what mislead me, all year I wrote the one on the left when drawing circuits, I guess physics teachers don't bother explaining the details when you study biology ^^

Thanks for the clarification guys, I feel so stupid, I thought I knew my flax

 

[Hermaphroditus]

A lot of the times you are simply learning about simple parallel plate capacitors in physics. They sometimes go a bit into electrolytic capacitors whenever you are talking about how dielectric substances change capacitance. There're some formulas for it, but in general you stick with a simple parallel plate type illustration for capacitors.

Most of what lower-level physics teaches in terms of electronics is simply V=IR, P=IV, Rt(series)=R1+R2+...Rn, 1/Rt(parallel)=1/R1+1/R2+...1/Rn, Ct(parallel)=C1+C2+...Cn, 1/Ct(series)=1/C1+1/C2+...1/Cn. And that's really about it. You maaaaaaaaay go into some Kirchhoff's rules, and do some branch/loop/node analysis, but they'll usually just stick to what I just said.

You may also learn stuff that involves the free-space permittivity (when dealing with simple parallel plates) and then dielectric permittivity when dealing with something like an electrolytic, but yeh.