Untitled Document

Physics Demo Number: 129

Approximate

Run Time: 5 min

Simple DC Circuits With Small Bulbs and Demonstration Meters

Demo Description

Two low voltage DC bulbs are hooked in series with a battery and Overhead Projector DMM.

One shows the current on that meter and uses the Pasco large demonstration DMM to view the voltage drop across one bulb, or both bulbs.

Scientific Principles

DC current flow
IR drops and Ohm's Law

Equipment

Pasco Demonstration DMM
Two DC Bulbs
Radio Shack DMM for Overhead Projector
6V Battery

Equipment Location

[B-2-2] , Kit (129)B
[B-2-2] , Kit (129)A
[B-2-2], Kit (129)A
On [A-2-2] by Electrolysis Apparatus

Instructions

Two meters, two bulbs, and a 6 volt battery are seen hooked up so that a current flows through the two bulbs and the overhead-projector-converted digital multimeter on the right.

The Pasco Demonstration meter on the left is registering the fact that the voltage drop across the left bulb is less than the 6V emf of the battery.

Closer looks at the setup are given in photos two

and three.

The meters and bulbs live in Kit (129) A and Kit (129)B on [B-2-2].

The battery is on [A-2-2] .

Any hookup wires not in the Kit can be obtained from the wall hanger between [A] and [B] columns.