Home
Class 12
PHYSICS
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

Verified by Experts

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`
Promotional Banner

Topper's Solved these Questions

  • ELECTRIC CURRENT THROUGH GASES

    HC VERMA|Exercise Short Answer|10 Videos

  • ELECTRIC CURRENT THROUGH GASES

    HC VERMA|Exercise Objective 1|9 Videos

  • ELECTRIC CURRENT THROUGH GASES

    HC VERMA|Exercise Exercises|23 Videos

  • ELECTRIC CURRENT IN CONDUCTORS

    HC VERMA|Exercise Exercises|84 Videos

  • ELECTRIC FIELD AND POTENTIAL

    HC VERMA|Exercise Exercises|75 Videos

Similar Questions

Explore conceptually related problems

The power delivered in the plate circuit of a diode is 1.0 W when the plate voltage is 36 V . Find the power delivered if the plate voltage is increased to 49 V . Assume Langmuir-Child equation to hold .

The dynamic plate resistance of a triode valve is 10 kOmega . Find the change in the plate current if the plate voltage is changed from 200 V to 220 V .

The plate current in a diode is 20 mA when the plate voltage is 50 V or 60 V . What will be the current if the plate voltage is 70 V ?

A parallel plate capacitor is connected to an ideal battery of emf E through a resistance R and a switch. Area of the plates of capacitor is A, and d is the separation between them. Resistance to the displacement current can be defined as R_d = V//i_d , where V and i_d are instantaneous potential difference between the plates and displacement current, respectively. Find displacement resistance as a function of time.

Before the saturation state of a diode at the plate voltages of 400 V and 200 V respectively the currents are i_(1) and i_(2) respectively. The ratio i_(1)//i_(2) will be

In a vaccume diode, when the plate voltage is 40 V, the plate current is 10 mA. For a plate voltage of 160 V, the plate current is

When the plate voltage of a triode is 150 V, its cut-ff voltage is -5V . On increasing the plate voltate to 200V, the cut-off voltage can be

The slope of plate characteristic of a vacuum diode is 2xx10^(-2)mA//V . The plate resistance of diode will be

The plate voltage of a triode is increased from 225 V to 250 V, the grid voltage is changed from 4 to -4.7V to maintain plate current constant. The amplification factor of the tube is