The mutual characteristic of a triode is represented by which of the following graphs?

With a change of load resistance of a triode, used as an amplifier, from $50 \, k\Omega$ to $100 \, k\Omega$, its voltage amplification changes from $25$ to $30$. The plate resistance of the triode is.....$k\Omega$.

Which of the following are triode constants?

$A$ triode has a plate resistance of $10 \, k\Omega$ and an amplification factor of $24$. If the input signal voltage is $0.4 \, V$ $(r.m.s.)$ and the load resistance is $10 \, k\Omega$,then the output voltage $(r.m.s.)$ is ...... $V$.

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.

On applying a potential of $-1 \ V$ at the grid of a triode,the following relation between plate voltage $V_p$ $(V)$ and plate current $I_p$ (in $mA$) is found:
$I_p = 0.125 V_p - 7.5$
If on applying $-3 \ V$ potential at the grid and $300 \ V$ potential at the plate,the plate current is found to be $5 \ mA$,then the amplification factor of the triode is: