Date: Wed, 26 Apr 2000 16:00:13 -0500 (EST)

Author: Michael McFarland

Subject: Re: Pasco apparatus recomendations, h/e and Millikan oil drop



On Wed, 19 Apr 2000, Paul Nord, a neighbor only a projectile-launch down
the road, wrote:

> Can anyone share experiences with Pasco's photoelectric effect apparatus?

We have used this apparatus for at least seven years. We generally like
the Pasco apparatus. A digital multimeter now directly measures the
stopping potential across the apparatus's photodiode. Our old apparatus
did not allow this direct measurement of stopping potential. The Pasco
apparatus gives us much better results than our old equipment. Pasco
built this equipment sturdy and designed it well. A joy to use!

We have had two minor problems, however. On each of many of our green and
yellow Pasco filters, the steel strip (designed as a high-magnetic-
permeability anchor to which the variable-transmission filter is secured
magnetically) does not stick well to the filter mount. We have most
recently used superglue to make the steel strip stick to the filter
mount. In addition, the thumbscrew on the Support Base Assembly's
vertical tube does not support enough torque, unless you tighten it with a
pair of pliers.

(Switching to a related topic, I have had no success using the Pasco
voltage probe and Science Workshop 700 with this experiment. I think the
difficulty arises from the probe's low input resistance.)

> How about the Millikan oil drop apparatus?
> We've got some money to spend before the end of the budget year. :)
> Thanks,
> Paul Nord
> Valparaiso University


* * * * * * * *

Mike McFarland
Resources for Instructional Labs and Lectures

University of Notre Dame

225 Nieuwland Science Hall
Notre Dame, IN 46556-0338

219-631-5952 (FAX)