A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Perpetual
Machine of First Kind
The perpetual machine
is a hypothetical concept which provides mechanical work more than the heat
absorbed by it. Perpetual machine will continue forever without external
energy.
Perpetual
Machine of Second Kind
It is an imaginary
concept as per which, a machine which
can absorb heat from source and completely convert it into work without converting
it into internal energy.
Perturbation
Theory
A set of
mathematical methods for obtaining approximate solutions to complex equations
for which no exact solution is possible or known, generally involving an
iterative algorithm in which each new term contributing to the solution has
less significance than the last. In quantum physics, Feynman diagrams are used
to calculate the terms for the perturbation theory solution of interactions
between particles.
Peta
Prefix in metric
system denoting 1015 of physical quantity
Pfund
Series
The spectrum of
wavelengths formed due to electronic transitions from higher states to fifth
orbit of atom. The wavelengths fall in far infrared region.
Phase
(SHM)
Fraction of time interval that has elapsed since the particle crossed
the mean position of rest in the positive direction.
(or)
It
is the ratio of displacement of vibrating particle at any instant to the
amplitude of vibrating particle.
Phase
Constant
It is the initial phase of the particle in
SHM.
Phase
Plate
Device used to
produce phase difference or path difference in ordinary and extra ordinary
waves produced by plane polarized light.
Phase
Point
The instantaneous
state of a particle in phase space is represented by a point known as phase
point.
Phase
Space
In Heisenberg’s
point of view, the state of a single particle is determined by position
coordinates x, y, z and momentum coordinates Px, Py, Pz totally comprising six
dimensions. This space is called as phase space.
Phase
Velocity
The
phase velocity of a wave is the rate at which the phase of wave propagates in
space. This is velocity at which phase of any one frequency component of wave
travels. For such a component, any given phase of wave will appear to travel at
phase velocity.
or
When
a progressive wave of a definite wavelength propagates in a medium, the
velocity of propagation of its wave front is called phase velocity or wave
velocity.
Phase
(Wave Motion)
Ratio
of displacement of vibrating particle at any instant to the amplitude of
vibrating particle
or
It
is defined as fraction of time interval that has elapsed since the particle
crossed the mean position of rest in the possible direction.
Phase
A homogeneous
portion of a system that has uniform physical and chemical characteristics is
called as phase.
or
It is a Greek
word “appearance” and is defined as a physically distinct but homogeneous part
of a system which is separated from other parts of the system by finite
bounding surface. Thus, each different, physically homogeneous part of a system
is called as phase. For instance in water system consisting ice, water and its
vapor, ice is the solid phase, water is liquid phase and vapor is gaseous
phase.
Phon
A unit of
apparent loudness, equal in number to the intensity in decibels of 1000 Hertz
have perceived to be as loud as sound being measured.
Phonon
Hypothetical
particle introduced for defining quantum of vibrational energy associated with
atoms in crystal lattice.
Phosphorescence
Type of luminescence
in which emission of light occurs with removal of excitation source with decay
time of few seconds to hours or days.
Phot
A phot is
a unit of illuminance,
or luminous flux through
an area. It is given as one lumen per cm2.
Photo
Conductivity
Electrical conductivity that results from photon induced electron excitations in which light is absorbed. The phenomenon which is usually observed in photo conductors and other semi conductor devices.
No comments:
Post a Comment