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

The plate characteristic curve of a diode in the space charge limited region is as shown in the figure. The slope of the curve at point $P$ is $5.0 \, mA/V$. The static plate resistance of the diode will be ...... $\Omega$.

$A$ triode has a transconductance $(g_m)$ of $2.5 \text{ mA/V}$ and an anode resistance $(r_p)$ of $20 \text{ k}\Omega$. If it is used as an amplifier with an amplification factor of $10$, what is the load resistance $(R_L)$ connected to the plate circuit in $\text{k}\Omega$?

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 $\text{mA}$.

$A$ change of $0.8 \,mA$ in the anode current of a triode occurs when the anode potential is changed by $10 \,V$. If $\mu = 8$ for the triode,then what change in the grid voltage would be required to produce a change of $4 \,mA$ in the anode current?

The figure represents the variation of triode parameters ($\mu$, $r_p$, or $g_m$) with the plate current. The correct variations of $\mu$ and $r_p$ are given, respectively, by the curves: