In the figure,four plate characteristics of a triode at different grid voltages are shown. The difference between successive grid voltages is $1 \ V$. Which curve will have the maximum grid voltage and what is its value?

The amplification factor of a triode is $10$. When the plate potential is $200 \, V$ and the grid potential is $-4 \, V$,a plate current of $4 \, mA$ is observed. If the plate potential is changed to $160 \, V$ and the grid potential is kept at $-7 \, V$,then the plate current will be.....$mA$.

In an amplifier,the load resistance ${R_L}$ is equal to the plate resistance ${r_p}$. The voltage amplification is equal to:

The amplification factor of a triode is $20$,the trans-conductance is $3 \text{ mS}$ (milli mho),and the load resistance is $3 \times 10^4 \ \Omega$. Calculate the voltage gain.

Why is a vacuum tube called a valve in electronics?

If ${R_p} = 7 \text{ k}\Omega$ and ${g_m} = 2.5 \text{ millimho}$, then on increasing the plate voltage by $50 \text{ V}$, how much must the grid voltage be changed so that the plate current remains the same? (in $V$)