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

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:

The variation of anode current $(I_p)$ in a triode corresponding to a change in grid potential $(V_g)$ at three different values of the plate potential $(V_p)$ is shown in the diagram. The mutual conductance $(g_m)$ of the triode is.........$ m \text{ mho}$.

Coating of strontium oxide on a tungsten cathode in a valve is good for thermionic emission because:

In a triode valve,which of the following statements is correct?

In the space charge limited region,the plate current in a diode is $10\, mA$ for a plate voltage of $150\, V$. If the plate voltage is increased to $600\, V$,then the plate current will be.......$mA$.