Define Flashcards
(22 cards)
Define Magnetic Flux Density
Force per unit current length
Define tesla
Newtons per amp meter
Define magnetic flux
Magnetic flux density x cross sectional area (= B x A)
Define the Weber
One weber = one tesla metre
Define magnetic flux linkage
Magnetic flux x number of turns
Define capacitance
Charge per unit voltAGE or potential difference
Define the farad
Coloumbs per volt
Define the time constant of a circuit
Time for charge to have decreased to 1/e of its initial charge
Define proton number
Number of protons in the nucleus
Define nucleon number
Sum of neutrons and protons in the nucleus
Define isotope
Same element with the same number of protons but different number of neutrons
Define Activity (radioactivity)
Spontaneous and random emmision of a stream of particles in nuclear decay
Define the decay constant
The probability of a nucleus per unit time
OR
The fraction of nuclei that will decay in the next unit time
Define half life
Time taken for the number of undecayed nuclei to be reduced to half its original value into its daughter product
Define binding energy
(Energy equivalent of the mass defect of a nucleus) - energy required to seperate the individual nucleons
Define binding energy per nucleon
Binding energy / nucleons
Define intensity
Power per unit area
Define the distance measured in Astronomical Units (AU)
1 AU is the radius of a circular path round the sub followed by a body in 365(.25) days
Define the distance measured in parsecs
Distance from a base length of 1 AU that subtends an angle of 1 arc second
Define the distance measured in light years
The distance travelled by electromagnetic radiation (light) in one year
Define critical density
The density above which it is believed the expansion of the universe will slow down and reverse
Define Electric Field Strengjt
Force per unit positive charge
