User:Manuel Franco Jr./NOtebook/Physics Lab 307/Notes For Planks Constant

=Notes for Planks Constant= Day 1

Setup and Equipment
So there are 3 filters
 * Relative Transmission
 * Mercury Yellow Line
 * Mercury Green Line

DVM (Digital Volt Meter)

Inside the h/e apparatus are two devices: an Operational amplifier and....


 * h/e apparatus w/ 2 9 volt batteries
 * white reflective mask
 * white photo diode


 * Light Shield
 * Lens/grating assembly
 * Hg lamp (light Source Os-9286 by Pasco scientific) Line voltage Range 108-132 in vacuum/Power: 125 W max Freq. 47-63 HZ 115 V

Procedure 1 (Measuring the Charge Rate)
We turned on the Hg lamp and let it heat up. Then we set the lens where the image was sharpest on the white mask. The two filters are used corresponding to the color on the white mask (green to green) (yellow to yellow). So for the first set of data we used green. We set the green filter on the white reflective mask, and made sure that the color and the aperture were lined up with green being as sharp as possible. The trans. filter allows and X% of light to pass through.

Green Data
Voltage just with green filter .847 +/- .001 (Eventually found out that is was not important to the data.)

Green/ Green Fliter
 * 1) .) Relative Tran. 100%
 * 2) .) Voltage .841 +/- .001 V
 * 3) .) Discharge time 14.25s,18.25s,17.66s,

We noticed that the 100% rel. tran. filter was not the same as just having the green filter .841 does not equal .847. We readjusted for better results. After talking to Mr. Koch he said that this was fine, but we started over any way. So what we are measuring is the charge time. The time it takes for the stopping potential to be reached. (From 0 V to the original Voltage). The of rate of charging.

Voltage just with green filter .9005 +/- .0005

Green/ Green Fliter
 * 1) .) Relative Tran. 100%
 * 2) .) Voltage: .883 +/- .001 V
 * 3) .) Discharge time: 14.97s, 14.06s, 16.41s

Green/ Green Fliter
 * 1) .) Relative Tran. 80%
 * 2) .) Voltage: .884 +/- .001 V
 * 3) .) Discharge time: 26.03s, 20.87s, 16.9s, 13.4s, 15.78s, 12.75s, 13.16s (The first two are going to be ignored I don't know what David was doing?) >:(

Green/ Green Fliter
 * 1) .) Relative Tran. 60%
 * 2) .) Voltage: .883 +/- .001 V
 * 3) .) Discharge time: 25.8s, 19.75s, 18.31s, 17.72s

Green/ Green Fliter
 * 1) .) Relative Tran. 40%
 * 2) .) Voltage: .882 +/- .001 V
 * 3) .) Discharge time: 28.44s, 23.66s, 16.56s

Green/ Green Fliter
 * 1) .) Relative Tran. 20%
 * 2) .) Voltage: .882 +/- .001 V
 * 3) .) Discharge time: 84.44s,29.25s, 50.00s,

The base voltage changed on us as we took measurements. It ranged from (.882 - .884 +/- .001 V)

Yellow Data
Yellow/ Yellow Fliter
 * 1) .) Relative Tran. 100%
 * 2) .) Voltage: .740 -/+ .001 V
 * 3) .) Discharge time: 15.40s, 18.09s, 17.22s

Yellow/ Yellow Fliter
 * 1) .) Relative Tran. 80%
 * 2) .) Voltage: .740 -/+ .001 V
 * 3) .) Discharge time: 17.88s, 15.53s, 16.69s

Yellow/ Yellow Fliter
 * 1) .) Relative Tran. 60%
 * 2) .) Voltage: .738 -/+ .001 V
 * 3) .) Discharge time: 22.85s, 18.41s, 22.50s

Yellow/ Yellow Fliter
 * 1) .) Relative Tran. 40%
 * 2) .) Voltage: .735 +/- .001 V
 * 3) .) Discharge time: 28.56s, 24.19s, 27.00s

Yellow/ Yellow Fliter
 * 1) .) Relative Tran. 20%
 * 2) .) Voltage: .735 +/- .001 V
 * 3) .) Discharge time: 45.40s, 46.50s, 49.35s

Value*q = KEi

Day 2

Determination of h
Measurements of 1st order

So the third and the fourth measurements are inconsistent data. After a while of using the apparatus the stabilized. As I was moving the lamp to align the color with the aperture, it increased in temperature. I'm guessing the lamp wasn't "warmed up" for the first two measurements? So we are going to disregard the first 2 measurements.

After talking to Dr. Koch, we come the realization that our voltage is too small, our data was not correct.

Measurements of 2st order

Ultraviolet
(We decided to do part 1 with Ultraviolet)
 * 1) .) Relative Tran. 100%
 * 2) .) Voltage: 1.6585 -/+ .0005 V
 * 3) .) Discharge time: 18.91s, 17.18s, 17.11s


 * 1) .) Relative Tran. 80%
 * 2) .) Voltage: 1.6735 -/+ .0005 V
 * 3) .) Discharge time: 27.30s, 26.25s, 30.69s


 * 1) .) Relative Tran. 60%
 * 2) .) Voltage: 1.6545 -/+ .0005 V
 * 3) .) Discharge time: 36.56s, 30.35s, 31.09s


 * 1) .) Relative Tran. 40%
 * 2) .) Voltage: 1.6795 +/- .0005 V
 * 3) .) Discharge time: 23.91s, 19.32s, 34.35s, 37.22s, 35.91s, 37.90s


 * 1) .) Relative Tran. 20%
 * 2) .) Voltage: 1.6715 +/- .0005 V
 * 3) .) Discharge time: 74s, 72s, 76.09s

First two for 40% were discarded.

Improvements in Data
Green Filter/Green Light

Yellow Filter/Yellow Light

Ultraviolet Light