Piirijännite

Piirijännite, often translated as circuit voltage, refers to the electrical potential difference between two points in an electric circuit. It is the driving force that causes electric charge carriers, typically electrons, to flow and create an electric current. Voltage is measured in volts (V) using a voltmeter. In a DC (direct current) circuit, the voltage is constant, while in an AC (alternating current) circuit, the voltage varies over time.

The source of piirijännite can be a battery, a power supply, or a generator. The magnitude of the voltage determines the strength of the electric field within the circuit. According to Ohm's Law, the relationship between voltage (V), current (I), and resistance (R) in a circuit is given by V = IR. This fundamental law highlights how voltage is directly proportional to current for a given resistance, and directly proportional to resistance for a given current.

Understanding piirijännite is crucial for designing, analyzing, and troubleshooting electrical systems. It dictates the power delivered to a component (P = VI) and is a critical factor in determining the safety of electrical devices and installations. Different applications require specific voltage levels; for instance, household appliances typically operate at mains voltage, while electronic devices often use much lower voltages supplied by adapters or internal power regulation.