Parallel Switch OR - Electronic Circuits Step by Step

Parallel switches behave like OR because either branch can complete a path. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Parallel switches offer alternate paths

In a parallel network, either branch can connect the lamp to the source return.

\text{parallel branches} \Rightarrow \text{either path can close}

One closed branch is enough

Close the upper branch while the lower branch stays open. The lamp is on.

\text{closed OR open} \Rightarrow \text{on}

Either branch can do it

Open the upper branch and close the lower branch instead. The lamp is still on.

\text{open OR closed} \Rightarrow \text{on}

Both closed is also on

Closing both branches gives two conducting choices, so the lamp is on.

\text{closed OR closed} \Rightarrow \text{on}

Only both open turns off

The full table has four graph states. Parallel topology turns the lamp on when either branch is closed.

\begin{array}{c|c|c}A&B&\text{lamp}\\\text{open}&\text{open}&\text{off}\\\text{closed}&\text{open}&\text{on}\\\text{open}&\text{closed}&\text{on}\\\text{closed}&\text{closed}&\text{on}\end{array}