capacitor
a device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator
M field
The magnetic field is the area around a magnet in which there is magnetic force. Moving electric charges can make magnetic fields.
E field
a region around a charged particle or object within which a force would be exerted on other charged particles or objects
Electric field is defined as the electric force per unit charge
dielectric
dielectric material is a substance that is a poor conductor of electricity, but an efficient supporter of electrostatic field
anode
cathode
The cathode is the negatively charged electrode.
The cathode attracts cations or positive charge.
The cathode is the source of electrons or an electron donor.
The anode is the positively charged electrode.
The anode attracts electrons or anions.
The anode may be a source of positive charge or an electron acceptor
Thomson Tube
principles
superposition of E & M fd allow construction of wien filter
there's plate capacitor where the beam can be deflected by E field while or e will be deflected by helmholtz pair of coils in M field
e beams visible allow quan.analysis
In the T.tube,e pass a slit aperture behind anode & hit the luminous screen
theory
2nd part of exp (wien filter)
def. from E & M just cancel each other
const. using crossed E &M fd
1st part of exp
def. of e in E fd.
E field exp is smaller than theory
e release from cathode,->acceleratd by anode voltage Ua & pass E fd of a plate cap w voltge Up.the distance between the plate is d.formula related:
e moves on parabola shaped curve
def of e in M fd
if value x & y r read off ,specific charge can be determined
e will moves on circular track in m fd of HHoltz pair of coils
objectives
assemble velocity filter (wien filter) to determine specific e charge
investigate deflection of e in E & M
