Potential difference

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Potential difference

In physics

Physics

Physics is the natural science which examines basic concepts such as energy, force, and spacetime and all that derives from these, such as mass, charge, matter and its Motion ....
, the potential difference or p.d. between two points is the difference of the points' scalar potential

Scalar potential

A scalar potential is a fundamental concept in vector analysis and physics . Given a vector field F, its scalar potential V is a scalar field whose negative gradient is F,...
, equivalent to the line integral of the field strength

Field strength

In physics, the field strength of a field is the magnitude of its vector value.In theoretical physics, field strength is another name for the curvature form....
between the two points.

There are various types of potential difference related to the amount of energy

Energy

In physics, energy is a scalar physical quantity that describes the amount of Work_ that can be performed by a force. Energy is an attribute of objects and systems that is subject to a conservation law....
required to move an object from one place to another against various types of force

Force

In physics, a force is that which can cause an object with mass to change its velocity. Force has both Euclidean_vector#Length of a vector and Direction , making it a Vector quantity....
s.

In some engineering fields, "potential" is sometimes described as the 'across variable', whereas flux

Flux

In the various subfields of physics, there exist two common usages of the term flux, both with rigorous mathematical frameworks.*In the study of transport phenomena , flux is defined as the amount that flows through a unit area per unit time....
is the 'through variable'.

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Encyclopedia

In physics

Physics

Scalar potential

Field strength

Energy

Force

In physics, a force is that which can cause an object with mass to change its velocity. Force has both Euclidean_vector#Length of a vector and Direction , making it a Vector quantity....
s.

in electrodynamics, the potential difference corresponds to the amount of work
Work (thermodynamics)

In thermodynamics, work is the quantity of energy transferred from one system to another without an accompanying transfer of entropy. It is a generalization of the concept of mechanical work in mechanics....
that would need to be done on a unit electric charge
Electric charge

Electric charge is a fundamental conserved property of some subatomic particles, which determines their electromagnetic interaction. Electrically charged matter is influenced by, and produces, electromagnetic fields....
to move it from one point to the other against an electric field
Electric field

In physics, the space surrounding an electric charge or in the presence of a time-varying magnetic field has a property called an electric field ....
. P.d. is synonymous with voltage
Voltage

Electrical tension is the potential difference between two points of an electrical or electronic circuit, expressed in volts. It is the measurement of the potential for an electric field to cause an electric current in an electrical conductor....
and is measured in volt
Volt

The volt is the SI SI derived unit of electric potential difference or electromotive force, commonly known as voltage. It is named in honor of the Lombard physicist Alessandro Volta , who invented the voltaic pile, possibly the first chemical battery ....
s. It is the line integral of the electric field strength between two points. Also, if v is the p.d. in volts, w is the work in joule
Joule

The joule is the SI derived unit of energy in the International System of Units. It is defined as:One joule is the amount of energy required to perform the following actions:...
s (J), and q is the charge in coulomb
Coulomb

The coulomb is the SI unit of electric charge. It is named after Charles-Augustin de Coulomb....
s (C), then::
In mechanics
Mechanics

Mechanics is the branch of physics concerned with the behaviour of physical body when subjected to forces or Displacement , and the subsequent effect of the bodies on their environment....
, the gravitational potential difference between two points on Earth is related to the energy that would be required to move a unit mass
Mass

In physical science, mass refers to the degree of acceleration a body acquires when subject to a force: bodies with greater mass are accelerated less by the same force....
from one point to the other against the Earth's gravitational field. Units: joules per kilogram.
In fluid systems the potential difference is the difference in pressure
Pressure

Pressure is the force per unit area applied to an object in a direction surface normal to the surface. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure....
. Units: pascal
Pascal (unit)

The pascal is the SI derived unit of pressure, stress , Young's modulus and tensile strength. It is a measure of force per unit area i.e. equivalent to one newton per square meter or one joule per cubic meter....
s.
In thermal systems the potential difference is the difference in temperature
Temperature

In physics, temperature is a physical property of a Physical system that underlies the common notions of hot and cold; something that feels hotter generally has the greater temperature....
. Units: kelvin
Kelvin

The kelvin is a Units of measurement of temperature and is one of the seven SI base units. The Kelvin scale is a Thermodynamic temperature scale where absolute zero, the theoretical absence of all thermal energy, is zero ....
s.

In some engineering fields, "potential" is sometimes described as the 'across variable', whereas flux

Flux

Power (physics)

In physics, power is the rate at which mechanical work is performed or energy is transmitted, or the amount of energy required or expended for a given unit of time....
, which is the time rate of change of energy

Energy