Re: Impedance &c.

[Bob Sciamanda <trebor@VELOCITY.NET>]

Quantitatively,
W = VK = ERK/(r + R), which has no maximum, with increasing R.  The highest
value approached with increasing R is W = EK. ( E is the cell EMF, assumed
constant)

Bob Sciamanda
Physics, Edinboro Univ of PA (Em)
http://www.velocity.net/~trebor/
trebor@velocity.net
----- Original Message -----
From: "Bob Sciamanda" <trebor@VELOCITY.NET>
To: <PHYS-L@lists.nau.edu>
Sent: Wednesday, January 07, 2004 10:11 AM
Subject: Re: Impedance &c.


> The total energy delivered is W = V I T = V K, where K is a constant (as
the
> load R is varied) and V is the terminal voltage (across R).
>
> 1) If the cell is ideal (r= 0)  then both V and K are constant as we vary
R,
> and so W = VK is independent of R
>
> 2) If the cell is non-ideal (has r>0), then if  we
> a) lower R, I will increase, K will stay fixed, and V will decrease => W =
> VK decreases.
> b) increase R, I will decrease, K will stay fixed, and V will increase =>
W
> = VK increases.   IE., if r>0 W increases with increasing R - there is no
> maximum.
>
>
> Bob Sciamanda
> Physics, Edinboro Univ of PA (Em)
> http://www.velocity.net/~trebor/
> trebor@velocity.net