F.2 IS -电流(current)和电压(voltage)有甚么分别?
发布网友
发布时间：2023-07-09 00:03
共1个回答
热心网友
时间：2024-12-06 05:24
水点) current = 电流 (如水流) voltage = 电压 (如瀑布的水位差出现的水压) 想像一下这三者的关系吧!
1. Electric Current 1.1 Current is by definition the flow of electric charge. The SI unit of electric current is the ampere (A)
which is equal to a flow of one coulomb of charge per second. 1.2 The magnitude of an electric current is defined as the time derivative of electric charge I = Q / t
where Q is the electric charge in coulombs (ampere seconds); t is the time in seconds 2. Voltage 2.1 Voltage is the difference of electrical potential beeen o points of an electrical neork
expressed in volts [1]. It is a measure of the capacity of an electric field to cause an electric current in an electrical conctor. 2.2 Beeen o points in an electric field
such as exists in an electrical circuit
the difference in their electrical potentials is known as the electrical potential difference. This difference is proportional to the electrostatic force that tends to push electrons or other charge-carriers from one point to the other. Potential difference
electrical potential
and electromagic force are measured in volts
leading to the monly used term voltage. Voltage is usually represented in equations by the symbols V
U
or E. (E is often preferred in academic writing
because it avoids the confusion beeen V and the SI symbol for the volt
which is also V.) 2.3 Electrical potential difference can be thought of as the ability to move electrical charge through a resistance. At a time in physics when the word force was used loosely
the potential difference was named the electromotive force or emf—a term which is still used in certain contexts. 2.4 Voltage is a property of an electric field
not indivial electrons. An electron moving across a voltage difference experiences a change in energy
often measured in electron-volts. This effect is *** ogous to a mass falling through a given height difference in a gravitational field. 2.5 When using the term 'potential difference' or voltage
one must be clear about the o points beeen which the voltage is specified or measured. There are o ways in which the term is used. This can lead to some confusion. 3. Relationship 3.1 The relationship beeen current and voltage can be expressed by Ohm's Law 3.2 Ohm's law predicts the current in an (ideal) resistor (or other ohmic device) to be applied voltage divided by resistance: I = V / R
where I is the current
measured in amperes V is the potential difference measured in volts R is the resistance measured in ohms
参考: en. ***
