Understanding the Unit of Electric Current Flow: The Ampere
The term electric current flow refers to the movement of electrons through a conductor. The unit used to measure this movement is the ampere, commonly abbreviated as A. This unit is named in honor of the French mathematician and physicist Jean-Marie Ampère.
Common Measurement Devices for Electric Current
Electric current is commonly measured in 'amps.' There are various types of meters used for this purpose, each suited to different load sizes:
Ammeter: Used for larger electrical loads. Ammeters measure current directly and are connected in series with the circuit. Milliampmeter: Used for smaller loads and electronics. It measures current in milliamperes (mA). Volt-Ohm-Milliamp Meter: This versatile meter can measure up to 10 amps and combines functions of a voltmeter, ohmmeter, and milliammeter. They can cost anywhere from $10 to over $100, depending on the model and features.The Ampere: Defining Unit of Electric Current
The ampere, or simply amp, is the standard unit of electric current in the International System of Units (SI). One ampere is equivalent to one coulomb of electric charge passing through a cross-sectional area per second. Coulombs are units of electric charge derived from current and time.
Keeping the context in mind, here are the key concepts to understand:
Volt: This unit measures electric potential or voltage, which is how quickly electricity is moving towards a load. Watt: This unit of power, calculated by multiplying voltage by current, indicates the amount of work done per unit time by the load. Volt-Ampere (VA): This is another unit related to electric current, used to measure the apparent power of a system. It is the product of the voltage applied to the load and the current drawn by it. However, VA ratings can be higher than watt ratings when dealing with reactive loads, with the ratio between the two being known as the power factor.Common Misconceptions about Electric Current
Electric current flow is often inaccurately conflated with voltage or resistance. While these factors play crucial roles, the measurement of electric current remains solely in Amps or Milliamps (mA). When current is minimal, we use milliamps. Otherwise, we measure in amps. It is important to understand that voltage and resistance are not part of the ampere's definition but rather additional electrical parameters.
The simplest term to describe electric current is electricity. So, when electricity flows through a circuit, it is known as current. Whether it is a battery connected to something or an electrical device plugged into an AC outlet, the movement of this electricity is accurately referred to as current.