Our ancestors relied on fire for light, warmth and cooking. Today at the flick of a switch, turn of a knob or the push of a button, we have instant power. This is possible because of the electric current. Do you know what is current? In this article, let us learn and find how electric current has revolutionised modern-day living. It is one of the important discoveries that helped us transform our way of living. From the time we wake up till the time we sleep at night, our life is dependent on electricity. From the basic bread toaster and baking oven to the commonly used television all require electric current to operate. The most common device, mobile phones, uses the electric current to charge the battery for operation. Besides playing a major part at home, electricity also plays an important role in industries, transportation and communication. In this article, let us learn to define electric current as animportant resource that we are highly dependent on.
- Electric Current Definition
- Prerequisites for the Current to Flow in a Conductor
- What Is an Electromotive Force?
- Unit of Electric Current
- Visualising Electric Current
- Conventional Current flow Vs Electron Flow
- Properties of Electric Current
- Effects of Electric Current
- Heating Effect of Electric Current
- Magnetic Effect of Electric Current
- Chemical Effect of Electric Current
- Frequently Asked Questions – FAQs
Electric Current Definition
Let us now define electric current and also know about conductors and insulators.
Electric Current is the rate of flow of electrons in a conductor. The SI Unit of electric current is the Ampere.
Electrons are minute particles that exist within the molecular structure of a substance. Sometimes, these electrons are tightly held, and other times they are loosely held. When electrons are loosely held by the nucleus, they are able to travel freely within the limits of the body. Electrons are negatively charged particles hence when they move, a number of charges moves, and we call this movement of electrons as electric current. It should be noted that the number of electrons that are able to move governs the ability of a particular substance to conduct electricity. Some materials allow the current to move better than others.Based on the ability of the material to conduct electricity, materials are classified into conductors and insulators.
Conductors: these materials allow the free flow of electrons from one particle to another. Conductors allow for charge transfer through the free movement of electrons. The flow of electrons inside the conducting material or conductor generates an electric current. The force that is required to drive the current flow through the conductor is known as voltage.
Examples of conductors: Human body, aqueous solutions of salts and metals like iron, silver and gold.
Did You Know?
Silver is the best conductor of electricity.
Insulators: Insulators are materials that restrict the free flow of electrons from one particle to another. The particles of the insulator do not allow the free flow of electrons; subsequently, the charge is seldom distributed evenly across the surface of an insulator.
Examples of Insulators: Plastic, Wood and Glass
Prerequisites for the Current to Flow in a Conductor
Some of the prerequisites for the electric current to flow in a conductor are discussed here.The circuit includes an energy source (a battery, for instance) that produces voltage. Without voltage, electrons move randomly and are undirected; hence current cannot flow. Voltage creates pressure on the electrons, which channelises them to flow in a single direction.
The circuit forms a closed conducting loop through which electrons can flow. A circuit is said to be closed or complete when a switch is turned ON.
What Is an Electromotive Force?
The motion of free electrons is normally haphazard. If a force acts on electrons to make them move in a particular direction, then up to some extent random motion of the electrons will be eliminated. An overall movement in one direction is achieved. The force that acts on the electrons to make them move in a certain direction is known as electromotive force, and its quantity is known as voltage and is measured in volts.
Read More: Electromotive Force
Unit of Electric Current
Let us know what is current and the unit to measure it.
The magnitude of electric current is measured in coulombs per second. The SI unit of electric current is Ampere and is denoted by the letter A. Ampere is defined as one coulomb of charge moving past a point in one second. If there are 6.241 x 1018 electrons flowing through our frame in one second, then the electrical current flowing through it is ‘One Ampere.’
The unit Ampere is widely used within electrical and electronic technology along with the multipliers like milliamp (0.001A), microamp (0.000001A), and so forth.
Read More: Ampere
Visualising Electric Current
To gain a deeper understanding of what an electric current is and how it behaves in a conductor, we can use the water pipe analogy of electricity. Certainly, there are some limitations but they serve as a very basic illustration of current and current flow.
Water Pipe Analogy of Electricity
We can compare the electric current to the water flowing through the pipe. When pressure is applied to one end of the pipe, the water is forced to flow through the pipe in one direction. The amount of water flow is proportional to the pressure placed on the end. This pressure can be compared to the electromotive force.
Conventional Current flow Vs Electron Flow
There is a lot of confusion around conventional current flow and electron flow. In this section, let us understand their differences.
Conventional Current Flow vs Electron Flow
Conventional Current Flow
The conventional current flow is from the positive to the negative terminal and indicates the direction in which positive charges would flow.
Electron Flow
The electron flow is from negative to positive terminal. Electrons are negatively charged and are therefore attracted to the positive terminal as unlike charges attract.
Properties of Electric Current
After we define electric current, let us learn the properties of electric current. Electric current is an important quantity in electronic circuits. We have adapted electricity in our lives so much that it becomes impossible to imagine life without it.Therefore, it is important to know what is current and the properties of the electric current.
- We know that electric current is the result of the flow of electrons. The work done in moving the electron stream is known as electrical energy. Electrical energy can be converted into other forms of energy such as heat energy, light energy, etc. For example, in an iron box, electric energy is converted to heat energy. Likewise, the electric energy in a bulb is converted into light energy.
- There are two types of electric current known as alternating current (AC) and direct current (DC). The direct current can flow only in one direction, whereas the alternating direction flows in two directions. Direct current is seldom used as a primary energy source in industries. It is mostly used in low voltage applications such as charging batteries, aircraft applications, etc. Alternating current is used to operate appliances for both household and industrial and commercial use.
- The electric current is measured in ampere. One ampere of current represents one coulomb of electric charge moving past a specific point in one second.
- The conventional direction of an electric current is the direction in which a positive charge would move. Henceforth, the current flowing in the external circuit is directed away from the positive terminal and toward the negative terminal of the battery.
You shouldn’t touch electrical equipment with wet hands! Watch the video to know why?
Effects of Electric Current
After defining electric current, let us learn various effects of electric current.When a current flows through a conductor, there are a number of signs which tell if a current is flowing or not. Following are the most prominent signs:
Heating Effect of Electric Current
When our clothes are crumpled, we use the iron box to make our clothes crisp and neat. Iron box works on the principle of heating effect of current. There are many such devices that work on the heating effect.
When an electric current flows through a conductor, heat is generated in the conductor.
The heating effect is given by the following equation
H=I2RT
The heating effect depends on the following factor:
- The time ‘t‘ for which the current flows. The longer the current flows in a conductor more heat is generated.
- The electrical resistance of the conductor. Higher the resistance, the higher the heat produced.
- The amount of current. The larger the amount of current higher the heat produced.
If the current is small then the amount of heat generated is likely to be very small and may not be noticed. However, if the current is larger then it is possible that a noticeable amount of heat is generated.
Read More: Heating Effect of Electric Current
Magnetic Effect of Electric Current
Another prominent effect that is noticeable when an electric current flows through the conductor is the build-up of the magnetic field. We can observe this when we place a compass close to a wire carrying a reasonably large direct current, and the compass needle deflects. The magnetic field generated by a current is put to good use in a number of areas. By winding a wire into a coil, the effect can be increased, and an electromagnet can be made.
Read More: Magnetic Effect of Electric Current
Chemical Effect of Electric Current
When an electric current passes through a solution, the solution ionizes and breaks down into ions. This is because a chemical reaction takes place when an electric current passes through the solution. Depending on the nature of the solution and the electrodes used, the following effects can be observed in the solution:
- change in the colour of the solution
- metallic deposits on the electrodes
- a release of gas or production of bubbles in the solution
Electroplating and electrolysis are the applications of the chemical effect of electric current.
Read More: Electroplating and Electrolysis
Frequently Asked Questions – FAQs
Why are copper wires used as connecting wires?
Because they offer low resistivity for the flow of electrons.
What is the reciprocal of conductance?
Resistance is the reciprocal of conductance.
What happens to the resistance of pure metals and semiconductors with an increase in temperature?
The resistance of pure metals increases with the increase in temperature, and the resistance of semiconductors decreases with an increase in temperature.
What is the unit of electric conductivity?
mho/metre or Siemens/metre.
Which method is used for the absolute measurement of resistance?
The Wheatstone bridge method is used for the absolute measurement of resistance.
What are insulators?
Insulators are materials that restrict the free flow of electrons from one particle to another. The particles of the insulator do not allow the free flow of electrons.
Define ampere.
Ampere is defined as the unit of electric current that is equal to the flow of one Coulomb per second.
What is electromotive force?
Electromotive force is defined as the electric potential produced by either an electrochemical cell or by changing the magnetic field. EMF is the commonly used acronym for electromotive force.
What is an electric charge?
Electric Charge is the property of subatomic particles that causes it to experience a force when placed in an electric and magnetic field.
State Coulomb’s law.
The magnitude of the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of the magnitudes of charges and inversely proportional to the square of the distance between them.
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FAQs
What is electric current question answer? ›
Electric current is the movement of charges through a conducting medium with respect to time. In Physics, electric current is defined as the flow of charged particles, such as electrons moving through an electrical conductor. The higher the voltage or potential difference, the more the current flow.
What is electric current and its properties? ›An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume.
What are the effects of electric current answer? ›Thus, the two effects of electric current are Heating and magnetic effect.
What are the types of electrical current? ›There are two kinds of current electricity: direct current (DC) and alternating current (AC). With direct current, electrons move in one direction. Batteries produce direct current. In alternating current, electrons flow in both directions.
What is the basic unit of electric current *? ›The ampere, symbol A, is the SI unit of electric current.
What is the formula for electric current? ›Current is usually denoted by the symbol I. Ohm's law relates the current flowing through a conductor to the voltage V and resistance R; that is, V = IR. An alternative statement of Ohm's law is I = V/R.
How does electric current flow? ›The direction of an electric current is by convention the direction in which a positive charge would move. Thus, the current in the external circuit is directed away from the positive terminal and toward the negative terminal of the battery. Electrons would actually move through the wires in the opposite direction.
How is electric current produced? ›What is an electric current? To produce an electric current, three things are needed: a supply of electric charges (electrons) which are free to flow, some form of push to move the charges through the circuit and a pathway to carry the charges. The pathway to carry the charges is usually a copper wire.
What causes current to flow? ›Electromotive force means the force which makes current continuously flows through a conductor. This force can be generated from power generator, battery, flashlight battery and fuel cell, etc.
What are the three main effect of current? ›Hence, the three effects of electric current are heating effect, magnetic effect and chemical effect.
What are the 3 main effects on electricity? ›
- Heating effect.
- Magnetic effect.
- Chemical effect.
When an electric current flows in a circuit it can have one or more of the following three effects: heating, magnetic or chemical.
What device is used for current? ›An ammeter is a device which is used to measure electric current through a circuit. Electric current is measured in amperes, hence the name ammeter.
What device uses current? ›Most household appliances and consumer electronics—cellphones, laptops, microwaves, light bulbs, you name it—use direct current (DC) electricity.
What are the properties of current? ›- The time 't' for which the current flows. The longer the current flows in a conductor more heat is generated.
- The electrical resistance of the conductor. Higher the resistance, the higher the heat produced.
- The amount of current. The larger the amount of current higher the heat produced.
The direction of an electric current is by convention the direction in which a positive charge would move. Thus, the current in the external circuit is directed away from the positive terminal and toward the negative terminal of the battery. Electrons would actually move through the wires in the opposite direction.
What is dimension of electric current? ›I=[M0L0T−1Q]
Which of these controls the flow of electric current? ›A switch is the device which controls the flow of current through a circuit.
How do you measure current? ›It is measured in the unit of the Ampere, simply called “Amp,” (A). The most common way to measure current in a circuit is to break the circuit open and insert an “ammeter” in series (in-line) with the circuit so that all electrons flowing through the circuit also have to go through the meter.
What is the charge of current? ›...
The relationship between current I and quantity of charge Q.
| I = | I = Q ÷ t |
|---|---|
| t = | t = Q ÷ I |
How to find voltage? ›
When spelled out, it means voltage = current x resistance, or volts = amps x ohms, or V = A x Ω.
Why is current important? ›Current is one of the most important and fundamental elements within electrical and electronic technology. The current flowing in a circuit can be used in a variety of ways from generating heat to causing circuits to switch, or information to be stored in an integrated circuit.
What is the difference between electricity and electric current? ›...
| Electricity | Current |
|---|---|
| 1.Electricity is a type of energy that is created by the flow of electrons. | current is a charge flow per unit time combination. |
People use electricity for lighting, heating, cooling, and refrigeration and for operating appliances, computers, electronics, machinery, and public transportation systems.
How do you get energy from current? ›Electrical power is the product of voltage and current. P=VXI. P = V X I . Here P is power in watts.
What force causes current? ›Voltage is the electrical force that causes free electrons to move from one atom to another. Just as water needs some pressure to force it through a pipe, electrical current needs some force to make it flow. "Volts" is the measure of "electrical pressure" that causes current flow.
What happens if current is too high? ›If too much current flows, the fuse wire rises to a higher temperature and melts, thus opening the circuit, but destroying the fuse. A circuit breaker opens a circuit as soon as the current climbs to unsafe levels, and can be used repeatedly.
What causes current loss? ›Imperfections in electrical insulation lead to the flow of very small currents across them in transformers, overhead lines, underground cables, and other network equipment. These types of fixed losses are called 'dielectric losses' or 'leakage current losses'.
Which effect of current is used? ›Heating effect of current is used in the working of electric fuse.
What factors affect electric current? ›The strength of the electric current depends on the following factors they are, Conductor resistance and its cross-section. Conductor thickness and the material used to make conductor. The potential difference across the two points of the conductor. Electrons drift velocity and its number density.
What is chemical effect of electric current? ›
When an electric current flows through a conducting solution, chemical reactions take place in the solution. This is called the chemical effect of electric current. Some of the chemical effects of electric current are as follows: Gas Bubbles are formed at electrodes. Metals are deposited on electrodes.
What are the 2 dangers of electricity? ›- electric shock and burns from contact with live parts.
- injury from exposure to arcing, fire from faulty electrical equipment or installations.
These days it even powers many of our cars. You could travel to the most uninhabited areas of the earth and still find it in the clouds above you during a storm. Electricity takes different forms: coal, water, solar, wind, nuclear, hydro and solar.
What are the 4 sources of electrical energy? ›According to the U.S. Energy Information Administration, most of the nation's electricity was generated by natural gas, nuclear energy, and coal in 2020. Electricity is also produced from renewable sources such as wind, hydropower, solar power, biomass, wind, and geothermal.
What are the 2 types of resistance? ›Normally resistors can be classified into two types namely linear resistor and non-linear resistor.
What effects fault current? ›Fault currents are caused by very low impedance short circuits. These may be shorts to ground or across phases. The resulting high current flow can result in overheating of equipment and conductors, excesses forces, and at times even serious arcs, blasts, and explosions.
What are the two main effect of current? ›Following are two effects produced by electric current: Heating effect. Magnetic effect.
What is current made of? ›Particles called electrons come together, and the number of electrons flowing each second is the current.
How do you control current flow? ›The common devices used to control current in an electric circuit are circuit breakers, switches, fuses, rheostat, and surge protectors. Resistors are used to limit the flow of current in the electrical circuit.
Which current is used in daily life? ›The typical example of current AC is the current flowing household electricity and power lines from a wall outlet. You can use any electrical appliance in India if it meets the standard voltage of 230 Volts and the frequency of 50 Hertz.
What current uses battery? ›
DC stands for 'direct current' which means the current only flows in one direction. Batteries and electronic devices like TVs, computers and DVD players use DC electricity - once an AC current enters a device, it's converted to DC. A typical battery supplies around 1.5 volts of DC.
What are current signals? ›An electrical signal is a voltage or current which conveys information, usually it means a voltage. The term can be used for any voltage or current in a circuit. Alternating Current (AC) flows one way, then the other way, continually reversing direction.
What device limits current? ›A Resistor is a device which opposes the flow of charge in the circuit. Hence it is used to limit electric current flow in the circuit.
What element is current? ›Current Element is basically an idealized entity which represents infinitesimally small current sections which combine to constitute the bulk current flowing trough a wire. The concept of current elements is generally used in electromagnetics to construct theories.
What is called a current? ›Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms. The common symbol for current is the uppercase letter I. The standard unit is the ampere, symbolized by A.
What is the power of current? ›The power formula can be rewritten using Ohm's law as P =I2R or P = V2/R, where V is the potential difference, I is the electric current, R is the resistance, and P is the electric power.
What is the definition of electric current? ›Electric current refers to the flow of electricity in an electronic circuit, and to the amount of electricity flowing through a circuit. It is measured in amperes (A). The larger the value in amperes, the more electricity is flowing in the circuit.
What are the 3 properties of electricity? ›- The Volt. The pressure that is put on free electrons that causes them to flow is known as electromotive force (EMF). ...
- The Ampere. The ampere defines the flow rate of electric current. ...
- The Ohm. The ohm is the unit of resistance in a conductor.
Basic electrical quantities: current, voltage, power.
What are examples of electrical properties? ›Electrical properties are their ability to conduct electrical current. Various electrical properties are resistivity, Electrical conductivity, temperature coefficient of resistance, dielectric strength and thermoelectricity.
What is the best definition of current? ›
Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms. The common symbol for current is the uppercase letter I.
What are two definitions of current? ›: the part of a fluid body (as air or water) moving continuously in a certain direction. : a flow of electric charge. also : the rate of such flow.
What is the property of current? ›Properties of Electric Current
DC, or direct current, flows solely in one direction and is utilised in low-voltage applications such as aviation. Alternating current, or AC, travels in both directions. Alternately, AC is indeed the current that enters our homes, and it powers the appliances using electrical power.
According to the U.S. Energy Information Administration, most of the nation's electricity was generated by natural gas, nuclear energy, and coal in 2020. Electricity is also produced from renewable sources such as wind, hydropower, solar power, biomass, wind, and geothermal.
What is a simple definition of electricity? ›Electricity is the flow of electrical power or charge. It is a secondary energy source which means that we get it from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources.
What are the properties of electric charge? ›The three basic properties of Charge: Additivity of charges. Quantization of charges. Conservation of charge.
What are the properties of voltage? ›| Sl. No. | Differentiating Property | Voltage |
|---|---|---|
| 2 | Unit | The SI unit of voltage is Volts (V). Note: 1 Volt= 1 Joule/coulomb. |
| 3 | Denotation | Voltage is denoted by “V”. |
| 4 | Measuring Instrument | Voltage can be measured by using a Voltmeter. |
| 5 | Inter-relation | Voltage is the cause of the current. |
Watts is the SI unit of power (P). Volts is the SI unit of potential difference and EMF. Watts specifies the rate at which energy is transferred. 1 volt is defined as the difference in electric potential across a wire when 1A current dissipates 1 watt of power across the wire.
What waves have electrical properties? ›Electromagnetic waves are waves that have some electrical properties and some magnetic properties.