D4 Multimeter Guide

A GUIDE TO BUILDING CIRCUITS and USING A MULTIMETER TO MEASURE RESISTANCE, VOLTAGE, AND CURRENT PART A: USING THE BREADBOARD TO BUILD A CIRCUIT The "breadboard" consists of a block of white plastic with two sets of five rows of holes. Each set of rows looks like . . . . . . . . . . . . . . . . . . etc. . . . . . . . . . . . . where each dot represents a hole. These holes are receptacles in which the ends of a resistor can be placed to construct a circuit. Each of the 5 holes in a vertical column is connected to the others in that same column by a wire inside the white plastic, so you don’t see it. Each of the 5 holes in a vertical column is therefore electrically connected. A resistor can then be connected to another resistor by putting one end of each resistor in the same column. A resistor can be connected to other things (like batteries) with alligator clips.

There are two distinct sets of these rows of 5-hole columns. The upper set is NOT connected to the lower set. Suppose that we want to use the breadboard to construct the circuit diagrammed below:

The symbol | | in the circuit diagram represents a battery; the longer line represents the positive terminal, the smaller line the negative terminal. The symbol /\/\/\/\/\/\ represents a resistor.

Place the wire connected to one end of the resistor wire (labeled "C" above) in any hole -- say the top hole (i.e., row 1) of column 5. The wire connected to the other end of the resistor (labeled "D") can be placed in any hole except those in column 5. (Placing the opposite ends of a resistor in holes of the same column is the same as directly connecting the two ends of the resistor, because of the wire connecting all holes in a vertical column. This is called "shorting out" or "short-circuiting" the