Clifton Arnold
Newly Enlightened
Help sombody fast is the anode positive or negitive I stuck
I can't remember.
I can't remember.
No, no, no, you have this backwards!Wow! I've been studying electricity for over five decades, and I never knew that. So, if I'm getting it right, the positive terminal on a rechargeable being discharged is the cathode. But when being charged, current flows the other way and comes out of the anode, and now the anode is called positive -- even though the anode voltage is negative with respect to the cathode.
Electrical engineering tends to define things according to the expected normal direction of current flow. For instance, consider a diode. When this is forward biased the current flows in the direction of the potential difference from positive to negative, and the electrons flow the other way, entering at the negative and and leaving at the positive end. The anode is where the electrons leave: the positive terminal! Just the same as a cell under charge.The part of all this that's new is calling the anode positive because the current exits here. In electrical engineering circles it is refered to as the negative terminal and retains that definition regardless of which way the current is flowing.
There is no conflict between electrical engineering and chemical engineering, fortunately Unless polarity reversal has occurred, the positive electrode of the cell is always more positive than the negative electrode. Chemists and physicists do certainly agree about what is positive and what is negative, because regardless of which way the current is flowing the potential gradient between the electrodes does not change direction. When chemists are doing electrochemistry the actual voltage potentials at electrodes have everything to do with what reactions might be happening.The emphasis is on voltage, whereas in chemical engineering circles the emphasis appears to be on current. Upon thinking about it, I guess that makes sense. Chemists are concerned with the inner world of the battery and talk in terms of anode and electrode, while electricals are concerned with the world external to the battery and talk in terms of positive and negative.
Hi - Mic here, newbie in Cairns Australia.
Aviation Engineering (EASA & CASA) is teaching 'electron flow' as opposed to 'conventional current flow'.
Electron flow from -ve to +ve around the circuit, and from +ve to -ve inside the battery.
Reverse of this for 'conventional current' flow.
Anode negative, Cathode positive during discharge
Hey have any of you guys got a formula for calculating the 'repelling force' (and units of expression for this) between like polaraties given in Coulombs?
I got as far as F = 'constant' x (Q1 x Q2 divided by the distance squared), however not clear on what the constant is all about. Also I think the unit is Newtons - is that correct?
Exam tomorrow, will check in later tonight - thanks in advance!! Mic