$A$ triode has a mutual conductance of $2 \times 10^{-3} \text{ mho}$ and an amplification factor of $50$. The anode is connected through a resistance of $25 \times 10^3 \, \Omega$ to a $250 \, \text{V}$ supply. The voltage gain of this amplifier is

Why is a vacuum tube called a valve in electronics?

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?

In an electron gun,the control grid is given a negative potential relative to the cathode in order to:

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 ...... $\Omega$.

Why is a vacuum needed in a vacuum tube?