Hands-On-Physics ELECTRICITY
Physics Concepts	- Bulbs in Parallel -

Real circuits are usually represented on paper as circuit diagrams. These electronic "blueprints" are used around the world for designing, understanding, and documenting real circuits. Circuits are pictured in a variety of ways, with photographs, sketches, and diagrams. Each kind of picture is a different level of abstraction, and each is useful in its own way.

Electronic components (like bulbs) can be attached in many ways. This is an example of a branching circuit. Circuits with branches are called "parallel" circuits. This example of two bulbs connected in parallel shows how circuit diagrams are created. A series of pictures shows this circuit represented in increasingly abstract ways; first in photographs, next as a sketch, then as a circuit diagram. We start with photographs. One photo shows wires connected by twisting them together, the next shows wires connected with a solderless breadboard. Both ways of connecting make the same circuit.

Figure P4a
Bulbs in parallel
with wires

Figure P4b
Bulbs in parallel
with breadboard

Figure P5
Parallel circuit sketch

Figure P6a
Parallel circuit diagram

Branch points are important features of parallel circuits.
In each picture above;

• locate the branch point where the current from the battery divides.
• Locate the branch point where the smaller currents join and re-form the main current back to the battery.

Figure P6b
Branch points