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

The amplification factor of a triode is $50$. If the grid potential is decreased by $0.20\, V$,what increase in plate potential will keep the plate current unchanged?

For a given plate-voltage,the plate current in a triode is maximum when the potential of

$14 \times 10^{15}$ electrons reach the anode per second. If the power consumed is $448 \text{ mW}$,then the plate (anode) voltage is .... $V$.

In a diode valve,the state of saturation can be obtained easily by

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?