According to the MIT School of Engineering, a battery provides an electrical charge due to the chemical reactions that take place inside it once it is connected into an electrical circuit. When a circuit connects the pos... More »

Potato batteries use the acids in the potato to start a reaction with two electrodes made of different metals that cause electrons to flow from one to the other through the potato, producing power. The potato acts as a s... More »

A lemon battery uses the juice inside the lemon as an electrolyte to facilitate electrons moving between a pair of electrodes inserted into the fruit. These need to be two dissimilar metals, such as a copper penny and zi... More »

A light bulb circuit works when the electric current flowing through the light bulb combines with the current flowing in the battery or power source. The filament and wires in the light bulb conduct electricity so that e... More »

Electricity moves through a circuit according to the polarity, or charge, of the power source and the various loads in the circuit. The power source of a circuit has positively charged and negatively charged terminals. E... More »

The RC time constant is the product of the resistance and capacitance of a circuit, or R x C. It is used to describe the rate of charging when a battery is connected to a resistor and capacitor in series. RC circuits can... More »

Current-limiting fuses contain a strip of metal within them that melts and quickly opens the circuit when the current in the circuit exceeds a rated value. The opening of the fuse is a protection mechanism meant to prote... More »