Overheard while the students discussed the difference between I vs. V characteristics of light bulbs and diodes.

 

Facilitating the process:

What else do we know?

Are we going to analyze predictions and measurements?  Or just measurements?

So forward voltage is one category, reverse is another?

So, what have we concluded so far?

Do we have to write down our data?

I’m going to keep writing down the data.

So basically what you had was…

Were you maybe reading it like…

So what should we put here?

 

Seeking Causes:

But it wouldn’t be through the LED.  The voltmeter was shorting out the LED.

So they’re about the same, what’s the reason for that?

 

Holding our thinking to the model:

So this is actually supporting our idea…

One thing I noticed was that as voltage increased, current increased

I thought it always had all the voltage right there.

The current is supposed to go up, according to predictions.

 

Seeking patterns

Was VR1 always 0?

So forward voltage is one category, reverse is another?

Do you have the same figures for positive and negative voltage? [Reply] Well, let’s compare.

So they’re about the same, what’s the reason for that?

I think there’s something wrong there.

So we can’t compare these to each other.

What I did was use Ohm’s Law, that you have to do that for each point individually.

I think the resistance will decrease because…

Diodes are crazy!

It probably works like a switch.