In the mutual characteristic curve of a triode,which point represents the cut-off voltage?

The transconductance of a triode amplifier is $2.5 \, \text{mS}$ (milli-mho) and its plate resistance is $20 \, \text{k}\Omega$. If the voltage amplification is $10$, find the load resistance in $\text{k}\Omega$.

In a triode valve,the amplification factor is $20$ and the mutual conductance is $10^{-3} \text{ mho}$. The plate resistance is:

In the grid circuit of a triode, an input voltage $E = 2\sqrt{2} \cos \omega t$ is applied. If the amplification factor $\mu = 14$ and the plate resistance $r_p = 10 \text{ k}\Omega$, find the $r.m.s.$ current flowing through the load resistance $R_L = 12 \text{ k}\Omega$ in $\text{mA}$.

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.

The relation between $I_p$ and $V_p$ for a triode is $I_p = (0.125V_p - 7.5) \text{ mA}$. Keeping the grid potential constant at $1 \text{ V}$,the value of $r_p$ will be . . . . . . $\text{k}\Omega$.