The saturation current in a triode valve can be changed by changing
(a) the grid voltage
(b) the plate voltage
(c) the separation between the grid and the cathode
(d) the temperature of the cathode

Open in App

Solution

(a) the grid voltage

Since the triode value consists of a space charge region near the cathode, this space charge region is affected by the grid voltage. If the grid voltage is made negative, it repels the electrons coming from the cathode and reduces current. If this voltage is made positive, it helps the electrons move towards the anode. Hence, this voltage is more effective in changing the plate current. Since, the saturated current in the triode is the maximum value of plate current, the saturated current in the triode valve is effectively controlled by the grid voltage. More negative is the grid voltage, less is the value of saturated current.

Suggest Corrections

Similar questions

Q. The grid voltage of any triode valve is changed from -1 volt to -3 volt and the mutual conductance is 3

\times

^{- 4}

mho. The change in plate circuit current will be

Q. The amplification factor of a triode operating in the linear region depends strongly on
(a) the temperature of the cathode
(b) the plate potential
(c) the grid potential
(d) the separations of the grid from the cathode and the anode

Q. The plate resistance and amplification factor of a triode are 10kΩ and 20. The tube is operated at plate voltage 250 V and grid voltage −7.5 V. The plate current is 10 mA. (a) To what value should the grid voltage be changed so as to increase the plate current to 15 mA? (b) To what value should the plate voltage be changed to take the plate current back to 10 mA?

Q. A triode valve has an amplification factor of

20

and its plate is given a potential of

300 V

. The grid voltage to reduce the plate current to zero, is

A triode valve operates at $V_{p} = 225 V$ and $V_{R}$ = -0.5 V.
The plate current remains unchanged if the plate voltage is increased to 250 V and the grid voltage is decreased to - 2.5 V calculate the amplifiation factor.

Join BYJU'S Learning Program

The saturation current in a triode valve can be changed by changing (a) the grid voltage (b) the plate voltage (c) the separation between the grid and the cathode (d) the temperature of the cathode

The saturation current in a triode valve can be changed by changing
(a) the grid voltage
(b) the plate voltage
(c) the separation between the grid and the cathode
(d) the temperature of the cathode