- Focus on Physics

Glossary W

Weak Interaction
Is one of the four fundamental forces
of nature. It is most commonly thought to be the cause of beta
decay and the associated radioactivity. It is carried by the W
bosons (W+ and W-) and Z bosons (Z0). The weak interaction affects:
neutrinos charged leptons quarks The weak interaction enables
all lepton and quark particles and antiparticles to interchange
energy, mass and charge – effectively change into each other.
Wheatstone bridge
Is a measuring instrument invented by
Sir Charles Wheatstone. It is used to measure an unknown electrical
resistance by balancing two legs of a ‘bridge circuit’, one leg
of which includes the unknown component.
Wimhurst machine
Is a device to measure atmospheric pressure
is an historical electrostatic machine, a form of electrical generator
for generating high voltages. It has a distinctive appearance,
with two large contra-rotating discs mounted in a vertical plane,
and a spark gap formed by two metal spheres. It was invented by
James Wimshurst in 1883. [more]
White Dwarf
Is a a star supported by electron degeneracy. A star like
our Sun will become a white dwarf when it has exhausted its
nuclear fuel. Near the end of its nuclear burning stage, such
a star goes through a red giant phase and then expels most of
its outer material (creating a planetary nebula) until only the hot
(T > 100,000 K) core remains, which then settles down to become
a young white dwarf. [more]
Wien displacement (Wien’s Law)
States that there is an inverse relationship
between the wavelength of the peak of the emission of a blackbody
and its temperature. Basically, the hotter an object is, the shorter
the wavelength at which it will emit radiation. [more]
Wollaston prism
The device consists of two calcite or
quartz prisms cemented such that they split into two beams which
are mutually perpendicularly polarized by nearly equal amount
in opposite directions. Named W. H. Wallaston. [hyperphysics]
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