In the circuit of a triode valve,there is no change in the plate current when the plate potential is increased from $200 \ V$ to $220 \ V$ and the grid potential is decreased from $-0.5 \ V$ to $-1.3 \ V$. The amplification factor of this valve is

Which of the following are triode constants?

The current in a triode at anode potential $100 \, V$ and grid potential $-1.2 \, V$ is $7.5 \, mA$. If the grid potential is changed to $-2.2 \, V$, the current becomes $5.5 \, mA$. The value of transconductance $(g_m)$ will be .... $mili \, mho$.

In a diode valve,the cathode temperature must be ($\phi$ = work function):

$A$ triode whose mutual conductance is $2.5 \text{ mA/V}$ and anode resistance is $20 \text{ k}\Omega$,is used as an amplifier whose amplification factor is $10$. The load resistance connected in the plate circuit will be.....$\text{k}\Omega$.

The plate current $i_p$ in a triode valve is given by $i_p = K(V_p + \mu V_g)^{3/2}$,where $i_p$ is in $mA$ and $V_p$ and $V_g$ are in $V$. If $r_p = 10^4 \, \Omega$ and $g_m = 5 \times 10^{-3} \, \text{mho}$,then for $i_p = 8 \, mA$ and $V_p = 300 \, V$,what are the values of $K$ and the grid cut-off voltage?