Severn Tunnel Junction railway station was created in 1886.

The Eurotunnel (aka The Channel Tunnel or Chunnel) is located just off Junction 12 of the M20 near Folkestone.

Exit the motorway at Junction 11a when travelling South and Junction 12 when travelling north.

See related links section for a map showing the local area, the postcode of the tunnel and full directions.

A thin junction diode which exhibits negative resistance under low forward bias condition is known as tunnel diode.

A thin junction diode which exhibits negative resistance under low forward bias condition is known as tunnel diode.

there is difference between doping levels.In normal PN junction diode we add 1 impurity for 108 atoms where as in tunnel diode we add 1 impurity for 103 atoms.there is a probability that electrons may penetrate through barrier.So will not disappear

in tunnel diode we get maximum current before barrier disappear where as we get maximum current after break down(there is no barrier)

this effect lies within a certain voltage limit of 0.4V.

When we consider the energy band structure in case of PN junction diode the fermi level lies inside the forbidden energy gap.In case of tunnel diode,the fermi level lies outside the forbidden energy band.

In tunnel diode, there is a topic about negative resistance region where as we cannot discuss it in PN junction diode.

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