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Show that the dynamic plate resistance o...

Show that the dynamic plate resistance of a diode is `2V/3i` where `V` and `i` are the plate voltage and the plate current respectively. Assume Langmuir-Child equation to hold.

Text Solution

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The dynamic plate resistance of the diode is `R = dV/di`.
The Langmuir-Child equation is
where `c` is a constant for a given diode. This gives
di/dV = 3/2 cV^(1/2)`. … (ii)
Dividing (ii) by (i), `1/I di/dV = 3/2V`.
or, `dV/di = 2V/3i`
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