Fortunately a variable capacitor is a surprisingly simple device, and one you can make yourself if you are ... to form the inductive part of a tuned circuit, but this coil is shorted out to ...

A simple circuit tester with two probes ... it’s always important to turn off the electrical circuit. However, some would ...

Adding more batteries to a simple circuit will increase the electrical energy, which will make a bulb brighter. Electricity can flow through the components in a complete electrical circuit.